rooted samsung admire former metro pcs

[Android Question]

1st question: how do i tell if i have successfully rooted my admire phone? I found superuser in the phone, been told would be there if i rooted it right, is that true? please advise

2nd question: now that it is rooted i have no apps. what is my next step, firmware, upgrade, download apps or.......

3rd question: if rooted properly is it still a metro phone or generic? will metro provide service if it is rooted? can i hook up with another wireless provider? like verizon?
note: phone can't pick up wireless signal or available networks.