Here's my quick and dirty read as someone who has only been to DL once, but it was just a couple of weeks ago.
Star Tours could be pretty tough. The best way to get on it without lines is via FP or standby at park opening, and the FP are all gone first thing in the morning. The only way you'll be able to ride this in a limited time situation would be to get in line at the end of the day after you've done everything else.
Space Mtn and Indiana Jones are good candidates for FP. Both are also located very close to the main entrance, so you can get an FP right away when you enter the park.
I would probably do this.
Enter park, head to Space Mountain. Grab FP. If the wait isn't too long, and you want two rides, ride it once now in standby.
Walk over to BTMRR. This is a high capacity ride, long lines are pretty rare. I'd ride it in standby.
Walk over to POTC, which is very close. Again, high capacity ride, long lines are rare, ride in standby.
Check the time. If you are close to FP return time, head to Indy, and get an FP there. If standby is not too bad, you could ride it that way too.
(I'd also consider single rider line, as the cars are big and it's common for two singles to end up in the same car, just different rows.)
If the FP return time isn't close, consider very seriously walking over to Haunted Mansion (it rocks) and/or the Winnie the Pooh ride (it's got some great dioramas, especially the Heffalumps and Woozles). Rare for either of these to have lines. (Then go to Indy, grab FP and/or ride standby or single rider.)
At this point your FP for Space Mountain is good, so head there, and use it.
Once you've done that, if you have FP for Indy, I'd recommend checking out another attraction or two in Tomorrowland (perhaps Buzz Lightyear, which is a hoot, or take a ride around the park on the monorail or railroad) OR heading back to Frontierland and Adventureland and checking something out there (re-ride POTC, HM, BTMRR, maybe Tiki Room? pretty fun), then use the FP for Indy.
Finally, head back for Star Tours. On one of these cycles back and forth, fireworks will happen, and IMHO if you don't have a lot of time it's not worth spending a lot of effort getting a "prime" viewing spot -- they are fireworks, if you can see the castle, you can see them fairly well.
In a nutshell, your main rides are grouped in two areas of the park, and you are grabbing FP in one area and then heading to the other to ride other things that are high throughput before grabbing an FP there, and then heading back. Back and forth, while it's more walking, you aren't waiting in lines.
