Fix Issues #20, #24, #25, #26, and #27

I wanted to try out contributing to SRB2P since I have been modding the game for a while and have gotten familiar with the game's code. This merge request aims to fix the specific issues listed below:
#20, #24, #25 (closed), #26 (closed), #27 (closed)
Thanks in advance for your consideration. I am open to any suggestions regarding code, commit, and merge request style.