I'm still running with the slowdown issue even with the lastest version of the base rom on zsnes, and I didn't add any sprites yet. But I thought of something, I changed Mario's position in the overworld in a way to not activate any events when I get the exit. Could it be related to this? Note that I've also set the sprite header to 8. And if I still have this level issue, do I have no other choice but to run the rom on a more accurate emulator like snes9x? And how do I record a video of my gameplay on snes9x?
-------------------- "SMW2 The Adventure Continues": Coming soon (maybe)
The latest version of ZSNES was created over 13 years ago. The emulator at this point has been completely abandoned and does not function properly in a modern SMW hacking environment. If you use ZSNES these days, you should expect your romhacks to run poorly. The slowdown you're encountering is a result of ZSNES being unable to handle modern SMW additions like SA-1. There is no other option than to use a different emulator like snes9x.
Well, I know I can only have one exit, but can I use multiple goals to lead to the same exit? (For example: a key hole and a secret exit goal tape, since they both activate the same exit)
Also, I played an entry were the path branched into 2 ways to complete the level, but the alternate route leads to the main goal tape exit, and I also wonder if this is allowed.
Even if the keyhole and goal tape lead to the same internal exit, that would be counted as two exits. For your second question, you can make a level that has two paths that eventually converge at the same goal, but you should really ask yourself if your level will be stronger by doing that. If you really think your level design skills are strong enough to carry two level-sized alternative paths and do it well, then try it. I hope it pays off.