Many long topics have been written on this blog over autorouters. At the moment I am still not convinced that FreeRouter is worth it’s money. I might give it a try when it’s capable of routing only a small section of a PCB which I mentioned n more detail in: An alternative freerouting plugin
That is what I expected. FreeRouter is not a very smart autorouter, it just does signals and treats everything equally. Is it even possible to set priorities or limits?
Reserving at least one layer for GND is a decent strategy for a 4-layer PCB. 2-layer PCB’s are cheaper, but much more difficult to design properly. Usually there is no room left for a proper GND plane. Such a PCB usually “works” but fails EMC tests.
If you have a GND plane then placing the vias manually is not such a big deal. Just start a track from an SMT pin, then press v to attach a via to the cursor, and [End] to place it. (A bit annoying those keys are so far apart on the keyboard).