Solved it! Sort of. I've explained how for future users with the same problem.
Office simply won't let me paste a 27th bitmap in one macro. Even if I run my macro for 26 ranges and then manually copy and paste, it doesn't work. At first I made two macros: one for the first 26 ranges and one for the next 26, however this was pretty clunky. I figure that the office clipboard was full, but I don't know a way around this.
I ended up pasting everything as enhanced metafiles, which actually works better than bitmaps. Not only do they seem to be better quality, but now I can use the selectall feature (I couldn't with Bitmap). This appears to get rid of the 26 range issue, although I've only tried it with 32 ranges so far. As for the outline issue, I simply created a border around each range and selected an extra row and column on every side of the range, which works for me. It might be that using enhanced metafiles would solve that issue, too, but I don't know. Here's the relevant piece of coding:
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