Concrete – What type of screws and anchors are used for concrete

My vote is for option 3. I've never seen angled pipe flanges either, but you could make a couple for this purpose out of 1-ft lengths of pressure-treated 2x6 with a pipe-sized 45-degree hole drilled in each. Then anchor those to the walls vertically. That would give you the added advantage of spreading your anchors out a bit in the cinderblock, rather than having 3 or 4 smallish anchors on a 2" radius or whatever.

I don't like option 1 just because you probably don't accurately know the strength of the concrete ceiling either locally or across its span, and that option's failure mode could be disastrous. Not to mention the likelihood (as you mentioned) of hitting steel and needing to rent a core drill and use it upside down on the ceiling. Not fun at all.

My main concern with option 2 is the tension load the bracket anchors are going to see. These blocks are very strong in compression (and by extension any anchors used in them are strong in shear), but not strong at all in tension (and by extension anchors don't resist pullout forces).

Use larger anchors/screws. IMO this is the best option. There are dozens of different types of anchors, so it is possible to find one that will be larger but fit the smaller screw. Myself, I'd drill the rack and use the proper screw for the anchors you have.

Another possibility, since brick is pretty deep, is to use a longer Tap-Con style screw, like 3" say. You can drill past the old anchor point, but still have plenty of meat for the longer screw to bite.

Sure, you can plug the holes with wood but I would not trust a bike rack or similar item hung off such a makeshitft anchor.