Building a P-trap

Getting ready to install plumbing for new tub install, and wanted to know ahead of time if there are any limitations when installing the p-trap. I know that the standard trap is a fairly tight radius. If need be, could a trap be made with two 90o elbows with a straight connecting pipe at the bottom ? if so how long can connecting pipe be so that the trap still functions correctly? (1", 3", 12" ???) If not, is it because the trap operates more efficiently with a tight turn in a shorter length?

Also, where there will be no access to the plumbing after the tub goes in, is it better to use only glued joints in the ABS plumbing?

Thanks

A longer run would be more inclined to gunk up.
Glue joints are always better then slip joint where there is no access. In fact it's now a requirement.

I've made traps using street medium 90 bends.

I kinda thought that was the reason. Thanks

I was wondering...does plastic pipe cement ever go bad? If it's still in a liquid state, is it still good to use. Mine is a few years old, but still looks OK.

If the can has ever been opened, it is questionable. The cement should be very "liquidy". Any signs of gel-like texure is a no-go.

Thanks for the tip. Because the plumbing won't be accessible afterwards, I bought a new can. Better safe than sorry.