I'm still playing vanilla VF5, to this day the graphics look really good, Akira is hard to use I can't really combo well with him, Sarah is really fun and does good damage and love her options out of the flamigo stance, El Blaze is a little gimmicky
Akira has been toned down significantly since VF5 Vanilla... Honestly, if you're gonna learn Akira, I wouldn't even worry about his K+G:G knee if that's one thing you're sweating... His SPoD (Stun Palm of Doom) should only be difficult when it comes to knowing which direction to press on the 2nd and 3rd inputs... I can't honestly thing of anything else that would be difficult imo... Once you learn how to buffer directional inputs to do certain moves (like pressing 33 or 11 to do moves from crouching), things become really easy with him... What specifically are you having troubles with???
As for combos, from most of his launchers you can do 6KP, K+GK and that's easy damage. It's not his strongest, but it's a start, and you don't have to any of his multiple button strings... In Vanilla, after a launch, while holding 6 you could P,P,P,PK and that did some ok damage, but with the major system overhaul that was done in VF5R, and VF5FS, Akira can do those classic combos anymore...
Once you get some of those "nuisances" down, he'll become fairly easy to play with...
Sarah has gotten ridiculously better since VF5 Vanilla... She doesn't have to work to get in damage much as she did before. She has more options, albeit risky-- well, I guess not all of them are as risky as they seem once you look at frame data...
I hate El Blaze... He's like the new-age Pai in terms of annoyance to me... Still somewhat of a fun character, I just hate fighting him...