The Sox have (1) basically nobody but Sale who projects to be among the best at his position for a long time; (2) very little projectable talent in the minors; (3) lots of bad contracts that prevent them from adding veterans; (4) questionable talent evaluators at all levels; (5) a fickle fan base.
I think the Sox need to start from scratch. Expansion teams can be built in five years, that's the looming challenge.
Talent evaluators are a lot cheaper than talent. Sox should clean house in the scouting department, starting immediately. Then they should build a top-of-the-line scouting and development organization, whatever it costs. It would help to move some of the minor league teams closer to Chicago so fans can get excited about prospects sooner.
Then they need to get the talent evaluators something to work with. They are not going to be far from the worst team in baseball over the next several years; they must accept it and start stockpiling high draft picks by losing.
Meanwhile, the bad contracts will take care of themselves. As opportunities present themselves to unload veterans, the Sox should do so. They can free up cash (needed to pay for scouting and development) and make themselves even worse on the field in the short term. Any real prospects they pick up are a bonus.
The few players with trade value, like Sale, need to be evaluated for how good they will be in five years and not how good they are now. Pitchers are risky long-term investments; pitchers with stressful deliveries are even riskier long-term investments. Sale needs to be converted into at least three players with best-at-their-position ceilings who are still several years from those ceilings.
The fan base will not be happy with a last-place team, but guess what? The team's already in last place. The die-hards will appreciate the five-year plan and will still support the Sox. The bad contracts at least have recognizable names to pacify the few casual fans who might still come to the park. The Sox should replace them with less-expensive veterans who are more popular with the fans; they've historically done that a lot anyway. If they brought in, say, Buehrle then he would also eat innings and be a good mentor to younger players.
This is the plan I thought Ventura was hired for, but the team got even more of a bounce out of firing Ozzie than I expected, so it's a year behind schedule.