The Lucky feat is considered by many to be overpowered, and is banned at many tables (including mine). So that would make inspiration a bit too good, although I guess it depends on how generous the GM is with giving out inspiration. With the Lucky feat usage resets after every long rest; I wouldn't typically hand out inspiration so frequently (in any case it is very situational, of course).
Well bear in mind that if everybody is using the same mechanic, then it levels the playing field. I've found that with Inspiration as written everybody keeps saving it for something more important, and then they eventually forget them have it. But when you switch it to after-the-roll they suddenly remember they have it in important moments.
I've long thought about what I'd want in a sword-and-sorcery system, and two things I was hoping to find (and disappointed to not find) in the Modipheus system are:
An elegant sub-system for weapon quality
Two goals that seem contradictory but I think can co-exist are:
1) The standard RPG excitement/incentive around discovering higher quality weapons
2) The genre trope (at least, in Conan) of constantly using new weapons
The solution, I think, is for a system in which weapons suffer damage through use, and if you don't get them repaired eventually they become useless. Higher quality weapons would be more resistant to damage (and maybe more expensive/difficult to repair). Thus it's still desirable (and thus exciting) to find really well made weapons, but the main benefit they confer is just that they are more reliable. Even the best ones will break eventually, and knowing that means that if you lose them (for all the myriad reasons that might occur during an adventure) it's not the end of the world.
"Scene Transitions"
This is another "two birds with one stone" thing:
1) My ideal sword-and-sorcery campaign would consist of self-contained adventures all over the world, without my having to necessarily do all the travel and other "filler" in between. You know, like Conan
2) There's the problem (in all RPGs) of what to do with your loot.
My idea here is a kind of down-time minigame where you roll on tables and a narrative unfolds of what happens in between your adventures. How do you lose all that gold? What happened to your weapon? What allies/enemies did you make? How did you go from carousing in a seaport to becoming a pirate captain 1,000 miles away?
I think it would be a blast for the dice to basically generate those scene transitions we read in the Howard stories, so that I can start off the next adventure in the right place, probably once again penniless. The more gold you ended the last session with, the more starting benefits you are likely to have in this one, perhaps in the form of a quality weapon or particularly good horse, or maybe some specific story "cards" that you get to play once. E.g., "Ally in an unexpected place" or whatever.
Anyway, throwing those ideas out there in the hope that somebody bakes them into a good sword-and-sorcery game.