It's interesting to analyze this last place overall roster to see what is killing it.
At forward, for the top 6, the top 5 are arguably at least average in the league, and with time would be above average as Tkachuk and White continue to develop. Stone, Duchene, White, Tkachuk and Dzingel can score, and have a combined +/- of about 0, which should be a bit higher, but given defensive woes, 0 is pretty good.
The 6th forward is a problem, either Bobby Ryan who is spotty in the regular season but proved solid last playoffs (granted 2 seasons ago), or Boedker, whose low goal total and limited talent package make him a detrimental 2nd liner or overpaid, middling 3rd liner.
Pageau historically has been a quality 3rd liner, and the more motivated Zach Smith we are seeing this year also is value as a 3rd liner. Neither Tierney or Boedker round out the 3rd line with quality, but maybe a 2 for 1 trade for somebody solid here and we have viability. Those two playing regularly this year has hurt, with a combined -27 to show for it, they must go.
The 4th line has been a big problem, as Paajarvi earned his pay last year, but in his UFA year has not competed. Pyatt hit the wall. Nick Paul now looks like he has figured it out, so 2 more quality guys are needed here, in relatively cheap roles, and could even be Zach Smith + someone else when Formenton/Batherson move into higher lines next year.
Forwards, overall, are playoff calibre with retention, and if Formenton/Batherson are the real deal, will be very good if all return next year.
Defense is another issue BUT imagine if you simply spent some money here, and added a Jacob Trouba while letting Ceci walk. Ceci and Lajoie are the main drivers of minus defensive play on this team, and I believe neither has the jam to be part of a contender. Lajoie could develop an offensive upside, but he brings down the grit factor, so he might prove to be a trading chip.
Pairs under this scenario could be:
Chabot-Trouba super solid top 2
Jaros-Demelo both a bit iffy in top 4, but JBD is on the way too, could drop Trouba to here for balance
Harpur-Boro not frills, but keeps opponents on their toes, and could sub in others where opponent speed is an issue
The combined 5 current Sens defensemen in this picture are only -6 this year, and Jaros and Harpur should get better.
Goalies: 2 of Hogberg, Gustafsson, Condon, Nilsson
might need an upgrade, but Hogberg has been reasonable so far.
So, by replacing Ceci with Trouba, and moving out 6 of the 8 players who are -10 or worse in the current year, proving they can't really do their jobs, I see a quality team emerging with an investment of about $3M per year (Trouba for Ceci) + increases to Stone, Duchene and Dzingel. Which would be easily covered by more butts in the seats over the course of a competitive season. And no 4 seasons of sucking waiting to get top draft picks with an empty arena, and I haven't factored in some of the question mark guys like Brown and Norris.