Is 8 the maximum number of incoming peer connections?
The reference here for running the bitcoin daemon does not really clarify what maxconnections mean.
Furthermore, that maxconnections only controls the number of inbound connections and not outbound. Is this true?

maxconnections counts both inbound and outbound connections. If you have 8 outbound connections, you can only have 117 inbound connections.

Is 8 the maximum number of incoming peer connections?

No, 8 is the maximum number of outgoing connections.

I believe, effectively, blocking port 8333 will only stop peers from connecting to me (stops inbound) and not me connecting to peers (does not stop outbound). Is this right?

Yes, that's correct. Also, there's a setting to do this without firewall software - set listen=0

What implications do blocking port 8333 have on my bitcoin daemon from getting transactions? Does it get less transactions or get transactions slower?

That could happen in theory, but in my experience it still works pretty well.