You are right on one thing. The team has way too many bottom 6 players on bad contracts. The Beagle and Myers contracts are especially egregious despite them being serviceable players for us this series. Sutter and Eriksson are actually decent players and would be fine pieces at 3-4 million instead of 4.4 and 6 respectively. We have yet to reach the time where Eriksson's contract looks its worst. Roussel, Ferland and Baertschi's contracts are good value individually for middle 6 players (league average contract is ~3 million and they are ~average players), but having only 1 of the 3 playing is not ideal. Roussel's contract is actually still an example of about as good as you can hope to do with those sort of free agent signings.
The rest of what you are saying is pure nonsense.
If these signings were made to shelter the young players, it only makes sense to do so while these young players are still in need of sheltering. To complain that Horvat is getting tough match-ups is ridiculous because it is exactly what a GM would have hoped for when he drafted Horvat. Horvat is not sheltering anyone... he is getting lots of ice-time because he is a good young player and he deserves it. Same goes for Hughes, Pettersson and Boeser. They should be (and are) playing big minutes because they are the team's best players. Imagine how much you would be complaining if they weren't.
You know who is getting sheltered by the Myers, the Sutters and the Beagles of the world? Adam Gaudette, Jake Virtanen and Olli Juolevi. These are the young players that aren't yet at the level to play in those match-up situations, especially on the PK. Who got all the PK time this series? It was steady doses of Beagle, Motte, Sutter, Myers and Edler. Better they eat those tough minutes than either group of the young guys.