Is it better to fight on the inside or outside as a southpaw fighter?

By inside I mean inside their lead foot.

By outside I mean outside their lead foot.

The usual advice is to keep on the outside to set them up for the cross which has a nice free path to their chin while you are safe from their cross.

But isnt it a myth that the rear cross is the most dangerous punch to or from a southpaw? (especially for the poor orthodox fighter)

Isnt it actually the front hook that causes the most KO's and is most dangerous to/from a southpaw?

Isnt it easier to land and avoid the front hook from the inside?

Also isnt it easier to jab from the inside? (setting up the cross or front hook and beating the cross to the mark and being safe from their jab)

Is the original idea to stay on the outside flawed and its actually better to stay on the inside?

Southpaw are generally more slick.
I would say better put pressure on them = inside
Depends on your inside skill actually

The big reason that fighters are told, in a lefty/righty matchup, to keep the lead foot outside, is to keep the other guy in front of you. But...
The school of thought in boxing has long been that you never give up the inside punching position- not talking about range, but about being inside position-wise, if that makes sense. By keeping your lead foot outside his, you give up the inside position. In essence you take one of your hands out of the picture.
So you pick your spots and do some of both. Of course it also depends what your opponent is trying to do to you, what his strengths are, etc...