Hello Chad, you have actually asked a multitude of different questions here. Typically certain rods will be classified according to groups, F4 would be one example. There are a number of rods which fall into this category, E7018 is one of them, there are a number of other rods in this group: EXX15, EXX16, and then the other EXX18 rods(the XX would designate the various strengths of these different electrodes). So if you take a particular certification test that is described as using an F4 filler, the operator is qualified to use any of those rods that are of the same strength as that used in the test or lower.
     A vertical plate test is generally considered as a 3G test and qualifies the individual to weld flat, horizontal, and vertical. In order to be able to weld overhead you need to also take a 4G which is an overhead plate.
     FCAW testing can have some ins and outs to it. If you test with an E71T-1 electrode which is commonly referred to as flux-cored, gas-shielded wire you are also qualified to run self-shielded wire such as NR 211 and you can also run Coreshield 8. Here's the exception however, if the Coreshield 8 is going to be used for welding of seismic connections then a seperate qualification test is required. The AWS code doesn't differentiate between FCAW self-shielded and dual-shield qualifications, but FEMA specifications and contract language does, so here is where you can end up having to take seperate tests with FCAW(gas-shielded, self-shielded) in order to be qualified to use one process versus the other.   
     If you can get access to an AWS code book you can possibly determine how some of these things are laid out. Better yet, if you are an AWS member, see about attending one of the section meetings in your area and ask these same questions. Likely there will be many folks there who could readily answer your questions. Others from the forum will likely reply and be more descriptive and understandable about the details that you have asked about, so stay tuned. Best regards, Allan