The owners manual says to replace the (1) fuel filter, (2) air cleaner filter, and (3) fuel tank air filter every 50,000 miles.

Does this have to be done? Do you do it?

Also (4) how often if ever should you change the transmission (transaxel) filter? Doing so is not stated in the manual.

I've read some controversies about it and am looking to get some clarification.