British Expats - WestMids to Midwest CR-1 journey!

Hello all. Just wanted to say thank you to everyone that shares their knowledge and experiences here on BE. I've been lurking for a while, researching and researching and researching, and it's been an invaluable resource as my wife and I finally prepare to start a journey of our own. For me specifically, it's the humble West Midlands of England to the state of Illinois! So I thought I'd make a little home here as well to relay everything we've been doing as no doubt we will have plenty of questions going into the future and others may find it useful someday.

We're newly married and will be sending off the I-130 petition sometime over the next month hopefully. We're painfully keeping going with the long distance while we wait with frequent visits as work and money allows. Our evidence package so far will include two family affidavits, a couple of photos in each country, a screenshot of family/friends messages congratulating our marriage and a "joint" bank account statement, which we're using for fees. Does this sound likely to be accepted first time to everyone else? Just want to avoid being asked for more evidence, because I can't imagine what else we could provide. Otherwise, is N/A or None recommended for literally every field that doesn't need to be answered?

I didn't think the joint bank account would be possible because of stories I'd read on here, but a lovely advisor in Fifth Third Bank managed to set us up during one of my recent trips there. My wife had to be the primary account holder with me as secondary and I don't have access to cheques, they used my passport number as an identifier and I had to fill a W-8-BEN form. I'm still not sure what this form is exactly because the tax system seems so confusing to me... but apparently it exempts me from paying tax because I don't earn any US income? Anyway, they still had to use my UK address and contact details to show, alongside this W-8-BEN form, that I'm not actually a resident in the US, just being allowed equal access to a basic account. Hopefully filling in this form doesn't give us any headaches in the future, but the advisor seemed sure everything was in order. I just don't want to get in trouble or anything for not realising what I should/shouldn't be signing, which brings me onto my next question:

Is there anyone that we have to "officially" report to, when it comes to tax or incomes, now that we're married? Either in the UK or the US? I'm finding it difficult to get a clear answer because most results seem to relate to ID/passports etc; neither of us are changing our names at the present time to avoid confusion with all the form-filling side of things so that's not an issue right now. We're just wondering what happens with the "married filing jointly or separately" side that applies to my wife from next year - would she just do separately until, fingers crossed, everything is approved and we live together? Or would she still have to declare my UK income since we're married? I read something about a "ITIN" but I don't want to fall down a rabbit hole of even more confusion. Similarly, do I have to tell HMRC I'm married even though it brings no apparent benefit in the UK? I have a permanent 9-5 job so don't claim any social benefits or anything that complicates things. The matters of household income through marriage when you don't actually live together seems like a bit of a minefield so I wanted to check.

Anyway thanks for reading, apologies for all this overthinking and waffling, but just wanted to get this out of the way. If it's allowed then I'll keep the thread updated with our own timeline as we go along :)