He would know all the same people he knew before he got married.
He is a fictional character and this is not possible.
cat women, penguin, joker, bane
The Marvel superheros and the villains.
If Batman got married, it's likely that the Joker would not receive an invitation. Their tumultuous and adversarial relationship makes it clear that Batman would want to avoid any chaos or disruption on his special day. Additionally, inviting someone like the Joker could lead to unexpected and dangerous situations, which Batman would surely want to avoid.
The Joker would not invited.
Most of the rogues' gallery (Riddler, Penguin, Two-Face, etc.), with the Joker probably the least likely of all.
Most people would not get an invention. Inventions are few and far between even among fictional super heroes.
Heath Ledger
Any one of the rogue gallery would not get an invitation, but if you were to choose, highest on that list would be the Joker.
Spiderman
Only Batman knows
He was/is not married. As far as anyone knows but how can you be sure