yes you can open it all up and add bank later,
I had a buying account for few months, then I turned it in to a seller acc afterwards
ok emails - big subject, in terms of pics and ip - gmail is meant to be safe, (same with if you set up another account with correct settings eg. yahoo, however ip can be shown on these accounts, so do not reply via ebay), but if you want to be extra safe, stay on unique screen - depends which emails you reply to, anything that goes direct to ebay via yellow button, will of course connect you to your login page..., but any other emails, eg direct to buyers email are ok..
there has been talk here about the reply to potential buyer without having their email eg
memberabc@ebay.com, it goes via ebay to the buyers email, you could always make sure you change ip, just in case there is a glitch and ip shows up somehow (although i doubt this really matters unless they are specifically looking out for you) - there was a gmail glitch a few months back for some users....I sometimes remember to, but usually I dont tbh.......
so you want to make a seller account, thats what you want phone for right? or is it to do paypal location verification? NO, the bank needs to be attached and then you can do this....you will only be asked for phone verification, again , once attached, in any case, so no point doing it before hand...
my advice? dont get your would-be out-laws involved without their knowledge, get your own number..
Opening new acc questions 
