If you cannot get a damn web 2.0 indexed naturally, then please, don't do SEO. URL submitting, especially through the same single Gmail account like many people here do is a very very very bad idea. You will connect all your web 2.0s and PBNs before you have even started. Catastrophic.
Another thing, checking history of web 2.0s is pointless. They will not be penalized ever. Maybe 0.00001% of web 2.0s you will ever see may have a penalty and kudos to the guy who pulled that off.
It doesn't matter if or if they aren't indexed, they will get indexed once you put some content on, that is not an utter shit. Especially if they already have a backlink profile.
Measuring web 2.0s by PA is a very bad idea, because that metrics sucks pee pee. Tumblrs have default PA of either 1 or 27. Most of those PA 27 have exactly ZERO backlinks, which means they are, yes, you guessed it, useless. There's a very good reason why you can get XY PA27 Tumblrs on Fiverr for $5.
And rule of thumb - The backlink is only as good as it is hard to get it. Think about that.