normal on boats with poor quality materials in the glasswork.
West is actually easy, as are some of the other epoxies (interlux)...but as you note, none of which are already mixed up ready to go. The prep work is the real work and on a boat such as yours, it may not be cost effective, especially if you have to pay to have it done.
Two ways to deal with it...pop each blister and let them dry out, may take months depending on the environment, once dry cut them down and refinish....else shave the top/gelcoat off, down to the glass and redo the finish (backwards from how the boat was laid up at the factory)Neither is easy or inexpensive.
Results are not guaranteed....some blister boats have the blisters reappear.
They are NOT structural, and will not prevent you from sailing...