I'll say it this way ... I could agree AND disagree with him
I can relate to his thinking as years ago ...
I twisted wrenches on Motorcycles for a living
and
There are some peeps around who on a daily basis tear up
BB's and Bowling Balls with the attitude of

......
"Doesn't Everybody"
Based upon info you provided above ... You don't seem like that
Yes ... h/c/i will work that motor with more stress
but
Your right foot does control that amount of stress
Lets just say ... h/c/i on your Stang has the potential of
greatly reducing the lifespan
Bottom line ... Sure ... more power will shorten lifespan
and
If you throw juice in the mix with your concerns ...
Well ... what do you think will happen

with even ... more power
Its all about how well your rings are NOW sealing
and
Your attitude about how often you ask it for max power
First order of biz is ... How much squeeze in the holes
Grady