Default [Q][Hellfire 10.2 jelly 2.4] too slow, something to set?

Hello guys,
I am currently using a Kindle Fire 7" 1st gen (rooted about 1 year ago and flashed cyano7), last week i decided to upgrade and I tried some roms but everyone of these present some little problems i didn't solve (rotation problem, error with keyboard process, usb mount storage problem..) with use of forum.
Finally I found ROM hellfire 10.2 jelly 2.4 (built Tue, Aug 27 and kernel 3.0.72+). Everything ok, no problems...but the kindle now is going very very slow: a long time to open app, and it is not so reactive as before. I don't play with it, I use kindle for gmail, web nav, twit, read books using amazon app and comics using ACV.. I think these apps are not so expensive in terms of hardware resources. Moreover, in order to increase the battery life I travel with wifi off and turn it on just to check notifications.

Is it normal? Does it depend on the hardware that it is not very performant using a rom so recently? Or can I set or check some parameters to increase performance?

Alternative could be flash an older rom or a lighter (but new) rom to increase reactivity and speed?

Thank you so much for any suggest!