The whole point of the PPC was that it could run all the old 68k software plus newer stuff optimized for the Power architecture. Most 68k software works just fine on PPC.
As for bin/cue vs cue/img vs img/ccd/sub etc....
The bin section is a bit for bit representation of the data on the data tracks of the CD. The cue file is a text file that describes the layout of the CD, so any software attempting to read the CD knows what format the tracks are in, what gap (if any) is between the tracks, what sector size is used, where the tracks are located in the data stream, etc.
img is essentially cue/bin in the same file; it's got a header at the top of the file, followed by the binary data. The sub file contains extra data found inside tracks (useful for when a track intentionally had bad blocks for copy protection, the sub will cause them to be skipped), and the ccd file is a configuration file for the Windows CloneCD software, so it knows when the image was written, what's on it, etc.
So most versions of Toast will look at a file, check if it's got a header (either img-style or iso-9660/High Sierra style) and skip past it, looking for the actual CD magic bytes. If it finds the magic bytes, it'll burn the CD with best-guess as to sector size -- potentially pulling that data from the header if it can find it.
Any CDs with regular sector formatting should burn just fine; if you've got one with multiple sessions, tracks with different sector sizes, or other odd characteristics, it may not burn correctly with Toast. Any software that will burn from a cue file should be able to make a perfect copy, unless there's copy protection on the original, in which case you need burning software that understands sub files.