There's probably no less than a cup of oil in the upper intake, tip it up in a bucket so it can drain.
There is a downside to port EFI that is overlooked, but has significant long-term impact on engine performance. That is the fact that only dry air is flowing through the intake system. Over time some of the oily vapor of blow by condenses and accumulates in the intake, since there's no fuel to wash it down. But it gets much worse: EGR is pumping exhaust carbon-soot into the intake too. When it combines with the moist oil vapor from the crankcase it makes a thick sludgy goo that coats the runners and plenum. Over time this process can cause flow restriction in the runners and liquid oil accumulation in the plenum, in old engines. Neither of these issues exist on a carburetor intake, the constant flow of fuel washes everything thru the system and into the cylinders.
All answers to your PCV questions are NO.
PCV has to have one side that accesses atmospheric pressure. The valve draws in blow by powered by intake manifold vacuum, working properly it draws slightly more volume than the blow by. The vacuum produced inside the engine draws filtered air into the engine from the side attached to the air filter, in the EFI it's that long hose to the airbox. During heavy throttle blow by is increased and vacuum is diminished. At low vacuum the PCV valve can not keep up with the blow by produced, and the positive pressure in the engine pushes the oily vapors out of the front tube into the air box where they travel thru the piping and back into the intake with the incoming air. Unless you do away with the recirculating system and run a "draft tube", both sides of the system must remain.
Contrary to popular opinion, venting the vapors without the recirculating system has no detrimental effect on the engine, provided the tube is of sufficient size to free-flow without creating backpressure in the crankcase. PCV was created as an emissions standard, it's not necessary for correct engine function. Every engine before the 60's and all diesels until very recently vented the vapor down a tube to the bottom of the engine where they were expelled into the open air. Not suggesting this, just FYI.
If you remove the PCV valve and let all the vapor backflow into the airbox, you will have a filter and airbox full of oil in short order. As already explained above, you can't block off the front tube either if the PCV valve is retained. To reduce under hood clutter, I run the front hose down to the bottom of the engine, with the PCV valve in back. If you do this, you'll need a filter element in the front hose since sometimes air is climbing the hose and entering the valve cover.