I think the Celts could win a game or two against the teams you mention, Celticsclay, and that would be cool to see. Winning a playoff series is still out of reach for this group at this stage of the rebuild, in my opinion.
I mean really?
How do the Raptors impress you that much? They are absolutely horrible on defense and really lacking in depth. I thought Demarre Carrol would be a nice addition for them, but he honestly has looked like a worst player than crowder at this point. I think Bradley and Smart would certainly annoy Lowry (and he has shown he can be thrown off his game in the playoffs in the past). They are really a similar team to us, a little higher top end talent, but way worse bench and depth (and probably coaching)
The pacers have a superstar, but they also have serious issues in the frontcourt where there best players at the moment are Jordan Hill, Ian Mahimi and Lavoy Allen. They make Johnson and Sullinger look like all-stars. Maybe George with some offensive sprinkles from ellis, stuckey and Miles could beat us, but I definitely would not call that a sure thing.
The hawks? I was penciling them in for being really good again this year but some things are just off. Maybe Carroll was really a difference maker for their cohesiveness but their players all seem to have slightly regressed with the exception of Teague (and schroeder off the bench). I would love to see that series, or really any of these.
I know you are not a linesmakers kind of guy, but for what its worth on a neutral floor those teams are all close to pick ems against the celtics right now (giving them a slight series edge because of home court advantage)