I can do the deliad on week 4 or 7? Its just preference?
Either works depending on how you feel after the first cycle. Unless you are doing one of the challenges in the beyond book then follow it including the deload.
Am I supposed to go 5 cycles forward and 3 back? Or just keep going forward as far as I can and then go reset back 3 cycles?
From my understanding this was a band aid until proper programming is detailed in the new book. If you are not making your prescribed reps then reset. I went 7 cycles when I started 5/3/1 but have followed the 5 forward/3 back since and it works for me.
Joker sets.... Just a preference for days you feel good and strong? Right?
Yes, when you are feeling good. I do Jokers very rarely.
And lastly... I am competing in a bench only meet in March, does 531 work well for a meet or should I be doing 351 instead?
I would say yes to 351, the 5/3/1 for powerlifting book uses the 351 version exclusively. Through trial and error, at 47 my joints feel better using 351 the majority of the time and not going for AMRAP's during the 5s week