I like JVR. He's always been a Bruins killer.
I do too... he's just too one-dimensional. Despite being 10 years older, I like having Marleau over JVR... Marleau will benefit from a few add'l PP minutes to fill the gap from JVR, and he also logs PK minutes. JVR is never on the ice in key defensive situations, which is why he only averages 14-16 minutes per game. He's a premier offensive threat for sure, but not well balanced player.
As for Matthews/Marner/Nylander... it really depends on how much they each improve again. On paper it goes Matthews>Marner>>Nylander, each had some tough stretches last year - Matthews lost 20 games due to 3 different injuries (shoulder, concussion and I forget the third issue); Marner had a VERY sluggish start to the season, but was by far their MVP after the all-star game. Nylander slightly improved, and showed a few stints of greatness.
Your numbers aren't too far off... Nylander can get extended before Matthews and Marner, and the talk was $6M-$6.5M range (comparable to Pasternak and Ehlers). With the cap increase in effect now, I could see it going to the 7-ish range. There's a possibility that Nylander might opt for a cheaper bridge deal, and try to get himself into that $8M-$9M range in a couple of years.
As for Matthews and Marner, again... depends on the kinda year they have. If Matthews gets more PP1 time, and potentially PK (which I believe he's trying to lobby for), he could get himself in and around the $10M mark. If Marner demonstrates he can consistently be the player he was in the 2nd half, he could be in the $10M range to. These two are like Stamkos/Kucherov - it's hard to really say who is better/more valuable.
Personally, I'd love to see Babcock put them on the same line together - and I'm not the only one.