Seattle Scar Removal doctors

Your scar does appear high.  I see this not infrequently.  Some plastic surgeons will  raise the position of the scar so that they can get rid of the old belly button hole. In someone with enough loose skin above the belly button, the old belly button hole (from the release of the BB from the surrounding skin) will move down far enough to remove it with all of the excess skin.  If the skin above the BB is not that loose, then it will not advance this much.  I leave the long tummy tuck scar down low where it belongs and simply close the old BB hole with a short vertical scar. In my opinion, this is better than raising the whole long tummy tuck scar too high simply to avoid that short vertical scar.  That is my opinion, other surgeons may feel differently.

If you are having a scar revision in order to significantly lower the position of the scar, you will need to have a fair amount of skin laxity above the scar to get it to advance inferiorly.  You may develop some laxity over time (a year, a few years?) but I doubt if you have much right now. So, unless your skin above the scar is currently much looser than it appears in your photos, do not count on much lowering of that scar from a scar revision. 

In order to do a proper repair of your diastasis recti, the abdominal skin would need to be raised up near the ribcage again in order to expose the full length of your diastasis.  Also, you appear to have a fairly thick subcutaneous fatty layer contributing to your abdominal protrusion, at least by what I can tell without examining you.  Thick subcutaneous fat, as well as excess intra-abdominal fat, which can only be reduced by dieting, will work against you getting a flat tummy even with a revision and diastasis repair.  The thinner you are, the better muscle/fascial and skin tightening, the better advancement and lowering of your scar, etc.  Without that, do not count on a scar revision and diastasis repair doing that much.  Perhaps a second opinion with a thorough examination would be helpful.

First keep in mind that the scar cannot be "removed". It can be improved, so that it is much less noticeable.

A combination of a resurfacing treatment such as fractional resurfacing and a dermal filler such as Radiesse should give you long lasting results.

It is not clear from your description what the scars on your legs are from.

it sounds like the spots are pigmented.

For best results to even out your complexion and balance pigment through out, you will most likely need a series of body peels, in addition to using a topical preparation that contains an exfoliant an a lightening agent.