I can't speak for 7.5, but with 7.1 there were a couple of differences. The Easy Install would add stuff like printer support. Given that 7.5 supports a fair number or printers it would get fairly large fairly fast. I also seem to recall it installing machine specific control panels and extensions.
Given my very limited experience with 7.5, I seem to recall it installing PPC and 68k code regardless of the circumstances. If you wanted to get rid of that code, you would need to get a separate application to strip it.
For something like a RAM disk, it is probably best to over-install and strip out what you don't need. For example, install printer support then take out the PPDs (?) that you won't use. Let it install the "libraries" then remove the ones that aren't used by many programs (e.g. OpenDoc). Using just the installer may sound easier, but you have to keep in mind that you are doing something that the developers probably didn't design it for (after all, RAM was pricey in the past).
Given my very limited experience with 7.5, I seem to recall it installing PPC and 68k code regardless of the circumstances. If you wanted to get rid of that code, you would need to get a separate application to strip it.
For something like a RAM disk, it is probably best to over-install and strip out what you don't need. For example, install printer support then take out the PPDs (?) that you won't use. Let it install the "libraries" then remove the ones that aren't used by many programs (e.g. OpenDoc). Using just the installer may sound easier, but you have to keep in mind that you are doing something that the developers probably didn't design it for (after all, RAM was pricey in the past).