@ vatas I did a quick search for the errors your getting. I think its related to administrative permissions on the PC and the lack of files. This link looks to be related and might be a solution. Otherwise always run the program in administrative mode.
http://www-01.ibm.com/support/docview.wss?uid=swg21496098@ Niza I believe the crashing problems on aggro was resolved a while back. It was related to a few edits Ender had made and was initially forked into this client. It was removed but I might still miss some issues that might unexpectedly happen. The only way for me to track them is to get the crash report and the only way to get the crash reports is to always have a pause at the end of the run.bat file. The client can then crash and after getting into safety you could copy paste it into here for me to take a look at and fix. Or I could try recreate the error which I seem to have no luck with.
About the rat on minimap I can also include with the other animal highlight fixes. I just need to draw a icon for them, gonna have to use my pro paint skills.