A few nerves are normal and probably a positive, it readies you to get everything in order. Better than being complacent, turning up here and having to get copy documents from back home, or elsewhere which can take for ever...
I'm on an LTVP. On that form they want to see a)income, and b)assets. That's so they can gauge that a) you can support yourself and won't be a burden on the state, and b) well the cynic might suggest that's so if you break the law, the state will know what to target.
I actually think it's a bigger picture. It's about profiling you. SG-ICA punch the data into the computer, and it says yes or no.
Now if you've spent the last few years in say Syria, with no declarable income, maybe you can see their point
As far as I know background checks (as you suggest) with that 'granularity', bank accounts etc., can't be made cross-border. I.e. I don't think they can 'credit check' you. Here (I believe), they're limited to something like an INTERPOL level check. But they'll take what you've declared on the forms, and simply consider whether 'it all adds up'.
I know those forms are very intimidating, esp. when you are from the EU, as we have pretty open borders and there is nothing like that in the EU.
Here, consider it like the Switzerland of Asia. There are lots of people that really want to move here, most good, but some less so; so the state need to profile everyone.
--- On the LTVP form, I forget precisely if they wanted addresses for the past 5 or 10 years, but I ended up listing about 5 addresses in 3-4 countries. It's pretty normal here for foreigners to move around quite frequently, so no big deal.
