Look guys sorry about posting while drunk but I have some ideas you might like. (no ranting lol)
Your in a uniqe postion to do alot with qfi lore and interaction/feature wise, alot of neat stuff never even thought of in qfg.
You can for exsample really
make infamy count and effect the story and character reactions some positvly some negativly.
You can also do alot of great stuff never allowed in qfi.
I relalize a may have hurt my credabilty a bit here but I have a few good simple to put in update ideas.
......................................................LORE:Lost relics of those who came before can be collected and put to use, maybe to unlock a secret puzzle and revale more hidden lore. Trigering the arcaolgist achievement.
.........................................RELATIONSHIP:Do a update of the game, where there is a gifting feature and hidden relationship bar with ina, kit and volarus. You know how the game hints at play your cards right making you think this already is in there?
Well you could follow up on that. Developing it a little in first games and continuing through all 5, when you make them, never allowed much in q4g 5, always later when the game was over which was a cop out. What is it?...a few dialog options, gifting 3 correct items and a cut sence followed by a little dialog at end of game? You could ad this in a couple weeks.
...........................INFAMY:Another idea, more options for infamy and odd and cool things you can do, that are not strctly speaking neccasary Maybe 4 new hidden things for each class?
............................GAMEPLAY COMBAT:An achivment for legetmently maxing your stats and getting the best stuff in act one before it was intended and breezing through the game after exsesivly grinding, like a feat of strength.
I know you guys hate stuff like that but people love it. Feeling like a total bad ass and managing through effort to do what they are not supposed to be able to do, well...seemingly. Though it should not be easy, that defeats the point.
.....................................ADVANCEMENT:Make it so if you get all achivments and do all 3 classes it unlocks a speical play through, not a pure cheat mode, but kind of like agd blue frog and battle mode but diffrent.
Rather special pristige options through game play, for a optional semi-non cannon play thoughrough just for fun. Make achivments mean something and keep people playing longer while they wait for next game.