Hold onto Embiid until he can get on the floor and consistently play 20+ productive minutes for half a season. Then look into shopping him.
For the rest of this season, I'd pretty much stay the course.
Around the time of the draft, I'd take the best player available in my draft slot who I think has a decent chance of being able to play alongside Noel or Okafor.
Next off-season, I'd gauge trade interest in Noel and Okafor. If I can get a really great haul for Okafor -- i.e. multiple established, relatively young talents -- I'd go for it. Otherwise, I'd trade Noel for any valuable, productive player assets I could get. Not looking for more draft picks.
I'd accept that with Saric, I'm probably waiting until I can offer better than rookie scale for him to come over.
In free agency, I'd target young players who have been undervalued by other teams. Guys who have shown an ability to produce but who haven't gotten the chance to secure a starting role. I'd also try to use my cap space to take on players of that description, as well. Basically, I'd do what Portland did last year.
Some examples of young(ish) UFAs:
Bazemore
Seraphin
Leuer
Budinger
I'd also look into signing Brandon Jennings on a short term, high annual value deal. Give him a chance to rebuild his value and maybe get an actual NBA point guard to run my team. Failing that, I'd consider doing the same with Rondo. At least he'd get the younger players involved. This is assuming I don't draft a top point guard prospect with a top 10 pick.
Then I'd look into signing a few older players on short term, high annual value deals as well. Guys looking for that last chance to play a significant role for a team. Guys with a reputation for good character who can act as mentors and on-court coaches. Guys who won't try to take a large role in the offense, who will get the younger guys involved first and foremost.
Examples:
Udonis Haslem
Richard Jefferson
Matt Bonner
Nene
Barbosa
David Lee
Randy Foye
There are no quick fixes for Philly, or for any rebuilding team. My goal would be to help get the infrastructure in place that allows a coach (Brett Brown or whoever) to actually install a system on both ends of the court and try to run real, honest-to-goodness NBA plays. I'd fill my roster with young role players for the draft prospects to compete against, and veteran players to keep the younger guys in line and accountable.