Well! Cut right to the chase! First, congrats on the tank find! To take your questions in order, I'll give my opinions, but I won't claim any of them are "final answers":
Tankmates: If you added those fish today as youngsters with your O, there is a chance that it might work out. When you're dealing with cichlids, a lot depends on the personality of the individual fish. It also seriously might not work out. Oscars can go through very aggressive stages. Jauguars and 5-star Generals are usually quite aggressive, and depending on their sex, might not want any other living beings sharing a 48" tank with them. If they do become aggressive, they are better equipped tooth-wise than your Oscar, and are quite capable of doing serious or fatal damage. It's a crap shoot, with the odds somewhat against you. I'll just say from experience that it sucks to lose a fish that way. A 72" tank would move the odds somewhat more in your favor, but even then it would be iffy. Cichlids are territorial, and will stake out and defend specific areas. A longer tank makes dividing into territories somewhat easier. I haven't tried that particular combination of fish, but even if I had, my results might differ from yours. I can't really recommend angels with an Oscar -- just too much difference in mass. Yellow labs are pretty, but have a whole different life style than Oscars. You might consider a second Oscar. If they hit it off, it's a nice combo. Maybe a different color than the one you have. There are quite a few possibilities.
As to food, the Hikari pellets are excellent, as are the bloodworms and brine shrimp. As your O puts on some size, the bloodworms and brine shrimp might not be so practical. There are freeze-dried crickets available, as well as freeze-dried krill. F-D plankton is also good, and maybe a better choice while he's small. IMO the main attraction of feeder fish is to entertain the fish keeper, though I've had a few fish (not oscars) that I just about had to give feeders for awhile. I like steak, but it would get boring after awhile, and is not nutritionally complete. I don't think any food maker has all the answers, so I don't use any one commercial fish food exclusively. There are lots of good quality pellets. Live or freeze-dried foods, like mealworms, crickets & other bugs, shrimp, etc are nice occasionally as treats. I'm not as adamantly against feeders as some are, but you have to recognize the risks (bringing diseases such as ich into the tank), and decide whether it's worth it. As you gain experience and knowledge, food for your fish, as for ourselves, can be a fun area to use some creativity.
Good luck, and let us know how things progress.





