Rodsthencones

I’d try raising the temp on the heat bed and maybe on the extrusion for the first layer.

The bed arcs up in the middle when it heats, so it may also be an issue with z offset. If it is 0.35 in the middle, but 0.45 at the edge, you might just need to smoosh the first layer more. Speed also effects first layer, so slowing down sometimes helps.

Find a big flat one layer test print and see what helps. Just don’t doal bunch of changes at once.

It might come loose if you heat the heat bed. At least soften enough to pry it off. The other option would be to finish breaking the glass. Then you could use acetone, or something to remove the glue.

You might consider a aluminum heat bed with a regular piece of glass on top. Look up heat beds on reprap and see how the diy community does it. They are cheap and easily replaced. I just print on the aluminum with painters tape. Sorry that it fractured like that, it happens. So having the glass glued down is not a good plan.