If i have got the tabs of the editor on the left side, geany crashes, if i try to open so many files, the place on the left for all files isn't enogh. So if there can be 10 tabs and i try to open 11 files, it crashes.
Which version are you running?
I had some similar issue but since I've updated to nightly devel snapshot http://nightly.geany.org/ its gone. Maybe it will solve your issue two, but keep in mind its a devel snapshot which might not running stable in other cases.