Agreed. The best bet would be to eliminate morphs that are not really needed (which is most of them in my experience) AND maybe get an SSD as well, but definitely it's the morphs. Eliminating unnecessary morphs will probably solve the problem with the error messages as well.
I am very careful with installing new morphs and in fact, I need to go over my own installation and eliminate a few that were added as part of a package. If for no other reason than to reduce the amount of scrolling I have to do when searching for a morph I actually want.
I actually keep two libraries on my drive, one is basically just the Fan Art characters I work on plus environments, clothing, poses and expressions. The other library is basically everything else. When I use the second library it takes quite a while to load a Genesis 8 character, we are talking about 5 minutes to load, when I am done morphing and adjusting I create my single slider morph and move it to the slim library where the same model will load in less than one minute, Dressing, posing and placing in environments does very little to increase that load time.
At least that setup works for me, since I rarely use Smart Content, I don't need to move the database to SSD either, but that is also another way to help decrease the load times, even if it is only by a few seconds.