I like your suggestions darkadonis. Adding on to that...
Disgaea 1/Disgaea 4 player here. I'm a FFTactics fan at heart so you know...
1. Combat animations too long: Yes, I get that you can turn them off. You have to with all the grinding. My problem is that once you turn them off you face the opposite problem, a lack of.. well, visuals. If you have them on you have to watch these animations that are just too long and imo too elaborate. I wish the game just gave you some on screen animations without cutting to a cutscene. This is one of my biggest qualms with the series (without getting into deeper mechanics).
2. Get rid of inifinite item god killing/duping that was in D4 and some previous ones. I thought this hurt the game just because it doesn't make much sense, it sowed the seeds of the games undoing, when I realized its necessity. You sort of have to do it too to clock in at a decent time, who wants to build more than one lvl 500 guardians when the option to dupe is there? Answer, you wouldn't when reverse pirating and capturing the innocent usually just gives you a lvl 4 guardian... that's 125 captured guardians from reverse pirating which is nuts. With duping I've got scores of items storing extra maxed guardians (which is another thing, can we get innocent storage as a fixed feature now?). Anyways, another problem is the act of repeat killing the item god and gency exiting. It takes no effort, just lots of gency exits and it takes no effort, just time, to get more gencys. It takes some 75 some IG kills, and not even kills versus the LoC IG (like should've been required, or scaling difficulty on the IG for each attempt) but no, just kill the regular old IG needed to be killed en masse, to get a trap maxed or whatever else before you then go to dupe that. That's boring and thats the easiest that requires the fewest IG kills, after that it goes way up. Which kind of leads me to emblems being too good (why would you not go for the item that adds to all stats?) and items like boots/glasses/belts not getting a lot of love from what i've seen.
3. Update the sprite designs. I was happy and sad to see the sprites in Disgaea 4 after having played 1. Was happy to see updated graphics of course but I was sad to see the sprite designs were essentially the same, along with ditching some of my favorite monsters (loved the D1 golem : ( )... units like the dragon look the same, design wise as it did in the original (not that it's a bad looking dragon at all), units like the zombie, however, I'd love to see a redesign for, maybe a couple zombie sprites to choose from ideally, etc. I would like to see some redesigns of the generic units too, the valkyrie, the archer, the mage classes, etc. It's getting visually stale and sort of weird to me that after four games that they look the same. I did like the character painter from Disgaea 4 a lot though and hope that's in the next one. Would like to see Male/Female versions of every class selectable upon creation rather than creating the opposite gender unit (for some) separately... you telling me there aren't male archers?
4. Sort of wish the game did turn orders differently. Not a fan of the "Alright, your entire army goes first, then your side...". I understand that with units being dispatched out of the base panel, it sort of forces that to be the design... however, I really think combat would be better if disgaea used something more traditional, like, speed determining turn order. What about ENEMIES getting a sneak attack? Why shouldn't this be possible in Disgaea? That is, what if enemies got their turn first.. it just seems sort of unfair that my units always get the jump, which is a big deal. It's sort of a blurr sometimes to see the battles too, in this format at least, especially with aforementioned animations turned off. One side moves all at once, delivering damage figures in quick succession... which allows for massive attack stacking in a game that already specializes now in one hit KO moves (as someone mentioned, once sp.attack multipliers go over 300%, it's one hit KO-ville basically). I hardly ever have to dispatch my full team either.
5. More elements. Wind, fire, ice... that's it? I guess it's 4 though, right? Forgot about star (which for whatever reason is abundant, easy to learn and doesn't have an associated resistance...). What about Earth? Water? Holy? Dark? Lightning? Its annoying to see moves that are clearly just LIGHTNING without the associated element for it (Take the guardian move "Shocking shock" as a perfect example, where he unleashes bolts, sparking the water the targeted units are standing in.). Wouldn't mind more status effects too... again, seems like that hasn't been updated since the original. How about a confusion like status? Something like Berserk too. Also, I don't think a move should be able to inflict status if it does zero damage (other than pure status moves like 'slumber' of course).
6. No more class DLC stuff: Was annoyed to learn that the DLC I got for the PS3 version was INCLUDED in the vita version along with lots of extra convenient features (some of which are massive time saves, see the handy cheat code to unlock all content at main menu). I'm curious as to why this is when they're both sony made systems, why is there version exclusivity? What if I'm a person who doesn't like handhelds and doesn't plan on owning one? I'd like to see a little more balance struck between versions because I'm not buying a vita just to play this game with a few extra perks.
7. Fighting itself doesn't yield much: IMO this game has become more item based than character based... yes, aptitudes matter but any newly created or captured character becomes a wrecker once you throw a good emblem on them. Guardians are ridiculous, considering you can have 3 + the specialized innocent for similarly boosting a characters weapon. I feel like I spent a lot of time fighting early on with my crew, just fighting in the item world or here or there, leveling my guys and in the end I can take a new character and make them better than one of my original units (who has been hacking and slashing since the first act) with a few easier chara runs. I wish just fighting itself could confer more bonuses to your characters than skill experience (which.. I'm sort of confused about what it matters when skills get such ridiculous multipliers anyways).
Disgaea has a lot of things I've never seen in these types of games, its got some originality there, it does a lot of interesting things and I like that they try to turn mistakes into "happy mistakes" and implement things that were bugs into the game as features but they need to go all the way with it and have it make sense. Again, with duping as an example, I like how it saves you time on having to level another item of that type to 300 (plus innocent duping whats on it) but I wish that it made more sense. Its hard for me to wrap my head around it from a story standpoint. How about instead of duping, you add a later game NPC called the "Forge master" or some shit to your base, who takes a certain amount of time to forge you a new copy of a piece of equipment you give him to hold, legendaries could take longer, higher leveled items, etc. It just feels weird and unnatural for your characters to have this narrative where they are duping items off of senators or item world clones (makes more sense than the senators but way more frustrating).Duping turns the game into a dupe fest too... I found myself torn between fighting and duping more powerful innocents/items. If you just gave the item to someone to dupe, you wouldn't be torn, you wouldn't have to waste time on duping and could get back to fighting.