I think there is more to applying shield pressure than looking at frame advantage for each move. Just because you have 2 more frames than me when I do move X doesn't mean you can get away from me super easily or hit me before I can hit you again. Link's biggest weapons are his bomb and boomerang. They add so much to the character that, I believe, is very hard to understand from reading numbers. Did you know that if you drop a bomb on someone's shield, it will bounce, covering their jump option, any slower option that requires them to stay put (sometimes even a grab) and then come down and hit their shield again? You can also catch the bomb and throw it if their option was to run away.
In the Marth matchup, I find the boomerang to be exceptionally powerful. Marth doesn't have a sex kick or anything that leaves a lingering hitbox that allows him to just run through boomerangs (similar to samus missiles). If you shield it, it comes back and I can throw it again. If you dodge it, and find that window to get in for a grab or something, then you have my returning boomerang to deal with, or for me to work with. This happens in many matchups and probably more often than people realise.
Pulling a bomb is slow, but you can drop that thing and it will hit as quickly as a shine. Another prime time to be jumped on and forced to shield is when you go for a bomb. Luckily, you have the bomb by the time you are shielding in this situation.
This doesn't mean you are never trapped in your shield without something to help you out, and Link's out-of-shield options do indeed suck, so there still is that. It's just that I find it doesn't actually happen that often. However, the big thing here is that when it does happen, it can mean you are dead.
I think Link's recovery from off stage is very good, but his from-the-ledge options are pretty weak. If you count that as part of the recovery (I personally do not, but I think some people do, which is fine) then I'd say his recover is only mediocre. So that is fine to say that he doesn't have a great recovery game.
As for hax dashing, I've been looking into it a bit. I feel like it is at least decent, and if they are spaced away like you describe MookieRah, then I don't think they will be able to hit you. Otherwise, you can cross them up or have some more options. I think Link's main weakness from the edge is that most of his aerials aren't safe even on hit so you can't do very much when the opponent is at low damage or if they are not in the right position.
I want to say that I don't think Link is viable at the highest level of play currently, but I do think he has a ton of potential that no one has fully grasped yet.