I'm in the same situation with my account. Just got my new One V and the first thing I did was connect it to the wifi and start installing my apps. Made my first grooveip call too.
No reason any of that will cause a problem activating the phone when I get to it.
I had just paid my $25 for service then a few days later swapped to the OneV and it warned me about how I would have to pay the whole $35 so I called VM and they refunded my $25 and let me add $10 and the OneV done deal and did not lose anything.