As far as the young bodies argument goes:
1. There are only nine forwards who will be 100% on the roster. Dadanov, Anisimov, Brown, Tierney, Tkachuk, Watson, Paul, Galchenyuk. We still ahve 4 spots for rookies. Watson and Paul shouldn't be blocking anyone from truly earning a spot. If Formenton, Logan Brown, Abramov, etc.. are any good, a vet can sit in the press box.
2. Batherson, Norris, Brown, Chlapik, Balcers, Abramov, Formenton, etc.. aren't subject to waivers that I am aware of so there is no chance of losing them.
3. Galchenyuk and Anisimov will probably be gone at the deadline. If the Sens suck, it opens up spots on the "back nine" of the season for rookies to get additional games. If the Sens are bad how many games do you see Anisimov playing before being traded? 40? 50? Galchenyuk isn't likely going to block Logan Brown for more than 50 games.
4. If we play too many young players it impacts our expansion draft protections.
5. If we play too many rookies they might be overmatched and develop bad habits.
6. If we play too many rookies and suck, guys like Tkachuk might not elect to sign extensions if we aren't making concrete progress in the standings.
7. There WILL be injuries and spots will open up as the season progresses. You always have to "budget" that you're going to be losing at least 200+ games among your 4 forward lines. That is two "extra" spots right there, even if they're spread out over the season. Assuming no one on the Sens is at risk of being lost to waivers, I'd much prefer the Sens sign cheap players and sit them in the press box than trade draft picks for injury replacements later.
8. We aren't signing a lot of AHL talent. Batherson, Norris, Brown, Chlapik, Balcers, Abramov, Formenton will be top-6 minutes in the AHL or elsewhere so it is not like we're totally missing development. Norris can use another 1/2 season, Stutzle, and Formenton too. Chlapik will probably make the roster and so will Batherson and Balcers. Really only Abramov and Brown are fighting for 1 spot that will open up to 3 spots (injuries even if no one is traded).