Help me do the comma

[Alex K]

Ben Davis,
do I have to do both 1.) and 2.) in order to be consistent? In my above sentence, putting them before and after the "and" as in
"has a nice flow to it, and, more importantly, that ..."
looks excessive to me
...

It isn't excessive.  However, it is optional, as Ben Davis stated.

I get that it is optional, I just wasn't sure whether the options are: do both 1. and 2. or neither, or whether I can pick and choose.

sometimes people put a period and start the next sentence with the word "And."

I did that in my first post here because SP told me that it was ok.

Since it is optional, you are not wrong to leave it off.  So you are going to have to do something else to try to convince us that you are not really a native speaker of English.  Your grammar and word usage are such that one would guess you to be a well-educated native speaker.

Yes, yes, enough with the flattery already