Hi Cal..
Questions are fine,
About using on same connection as your regular accounts. I have a LOT of kids, all have tons of FB accounts etc and
I am running a stealth client AND usually the next beta version under testing. I have never lost an account due to this yet.

I am almost surprised about it to be honest. It seems if the account is good legit looking and phone verified etc, its good to go. I am sure there is a limit per IP on FB, twittter etc but we stay under that.
Stealth vs Pro
Is really related to the scale of your IM projects, If you need more credits or more domains then Stealth is the way to go. If you only have sub 7 sites then just do pro, it will be sufficient. Stealth users tend to have 20 plus sites on average, and like me just dont have time to deal with the social love factor and we would rather just get it done. Same for small SEO Companies, they just need that base covered. The clients act the same for the most part.
FbFB is providing accounts for our users from Russia to China and his success rates for accounts is excellent, we are happy to have him. That said, any issues just hit him up on Skype, and we will fix anything that's not working. I would hit the accounts right when you get them as if there are issues its a lot easier for him to fix them right then.
Most of your concerns are totally valid I have read so far, just keep in mind this is not a BOT in the normal sense at all and is really the point of it at the end of the day. You load up a site, and all of a sudden your site starts getting some action, both social, your authors start getting followers and REAL traffic from around the world. No Proxy, but real IPs with long staying visits, multi page visits, its a whole new ballgame.