So here is my question, I'll use Friday as an example.
92 degrees outside, with about 55% humidity, no clouds at all sun
beating on my roof, heat index of 104. House stayed at the set
temperature of 76 all morning until about 2PM when the temperature
began to rise to about 78 and never came down again until about 8PM. My
unit ran the whole time never shutting off till about 8pm. Is this
normal or could there be a problem? I'm guessing it's normal due
the Sun and excessive heat but just want to be sure.

Sounds normal. You had about the worst outdoor conditions you typically
see, PLUS, Friday was a real windy day with Hurricane Dennis offshore from
you, right? Unlike a normal hot day, you therefore had lots of humid air
blowing around and infiltrating your house. In those conditions, your unit
can't keep up with the latent heat demands of all that moisture constantly
infiltrating, in addition to the usual heat load. Did you check the
condensate drip? I expect it was running like a faucet then.

Evaluate it again on a calm, hot, sunny day.

The most economical system is just large enough to keep up, or just start
falling behind, on the worst day. Bigger or smaller is less economical and
less effective.