My parents/future in-laws are driving me crazy

Your in-laws aren't traditional, they're rude. Don't share anymore details with people with endless criticism who offer no solutions to help. No pay, no say. Your future spouse needs to have a talk with them, because no way should you live a life where they will look down at your parents. This is a bad start to joining families. Stand your ground, you can do it.

This is similar to my situation. My parents are pretty traditional so they expected to pay for the wedding. My mom wants what's going to make me happy. We're having a small wedding anyways. She's quite frustrated with FMIL because she's not paying for anything, not even the rehearsal dinner yet keeps asking questions about things that are not her concern. It triggers my anxiety, frankly. FH told her we'd release details when we're ready but she doesn't listen. I just change the subject or leave the room if I can. It's worse when FH brings me questions his mom asks. FH are blending cultures so I actually asked FMIL what are some cultural traditions I can include, even though we're having a second wedding to honor FH's culture. She just brushed it off.

Well, if your in-laws want to be so traditional.............. they would not only be responsible for the rehearsal dinner, they would also be responsible for the liquor at the reception, the bride's bouquet, all the groomsmen and groom's family flowers, the groom's attire, the honeymoon and the officiant. The bride's family was "traditionally" responsible for all decor, bridesmaid's bouquets, brides family flowers, reception food, music, the bride's attire. The couple was traditionally responsible for their rings, photos and their marriage license (and once bridal party gifts became a thing, that didn't start until the mid 80s). Just saying your future in-laws are getting off cheap if they expected everything to be paid in the "traditional" way. ha ha ha.......... one of the reasons things have been shifting to the bride and groom so that others have no say when there's no pay. In the "traditional" days the bride had no real part in the planning other than selecting her bridal attire and her trousseau. Definitely not the way today's brides would tolerate, but back then the bride rarely had any money, she hadn't usually started her career yet, and her groom was barely into his and he was supposed to stay focused on providing the family home etc.

Hang in there, kiddo.............. tell your man not to tell you he's asking questions for his mom......he needs to be asking so HE knows what his wedding is going to be.

Why do your FILs even know how much your family is contributing?

Stop stop sharing details about the wedding, particularly about finances. What’s coming next is a huge list from them of people to invite. Maybe just respond with “oh no worries we have that handled”. Repeat frequently.

Share the details you want to with your in-laws but don't feel obligated to do so. If they aren't contributing to anything besides the rehearsal, then they should not have a say in some of the bigger decisions that you and your future spouse make.

This may be a conversation that your future spouse will need to have with their parents though. Boundaries should be set.