LAG - Latency Against Gamers.
Ok enough of the fun for now. Today I decided to test my game on some other computers. I soon founf out I had some weird bugs, but thats not the point. These computers weren’t the best, infact they are probably pieces from computers from years ago. My computer runs the game at 20FPS, my FPS meter counts 21-22 Lowest is around 17. When I post it online i see it drop by 5 FPS, so I bumped the FPS up by 5.

On the computers I tested it on one was fine on High detail until I entered the place I expected it to lag, it dropped to about 15 from 20. On the second computer on high detail it was at 11 FPS on high detail, and 4FPS lowest. I want even the crappy computers to play decently. On medium quality I have no lag at all. Ok so here are my questions:

Is there any way I can change the FPS on certain frames?

Would caching my MCs as bitmaps,which is causing the lag, reduce lag. Or should I change the images into bitmap pictures and replace the graphics inside the Mc with the same drawing, but as a bitmap.

And a question not related to the above. To increase accurate hitTesting and stopping walking through walls could I check to see if you are going to hit but at different distances. For example:
if(this._x +10 hitTest(_root.object)== false){
this._x +=10
}else if(this._x +9 hitTest(_root.object)==false){
this._x += 9
//and so on
Would mean alot more code, but would it be worth it?