So, "opcache" is meant to help a little of both #1and #2.
For several years, I have desired to get "caching" working on my Moodle. Here is my current logic. Since opcache is somewhat built into Moodle 2.6 and PHP 5.5.?, why not use it? Also, the installation seems fairly straightforward. In fact, this is the first time that I have succeeded getting a cache to work. So I would like to stick with it (until it breaks). I think I will continue working with it over my semester (Christmas) break, and see how it goes.
I am the most active user of my Moodle site, so I am going to use my own judgment, along with whatever statistics I can gather, to assess my progress.
Yep, one can only get so much performance from a VPS. At this point in time, the GoDaddy VPS that I have for experimenting fits my budget. I am getting 2GB RAM, 60GB disk space, a company that manages many systems, for around $30 US per month.
Howard, I certainly appreciate the time you devote to helping users here on Moodle.org. You will see me continuing to ask questions, as I now have a little time to experiment and learn. Thanks.