Event Hacking - What am I doing wrong?

Yeah manually with a hex editor is still the way to go due to zone doctors event editing issues. There is this one made by Everything that seemingly has an event editor included, but nobody can use it because it's made for Mac users only ;( http://www.romhacking.net/utilities/1267/

To account for larger events you'll need to utilize and master the B2 jump to/call sub-routine command, to jump to free space such as the expanded F banks, then you can either end the event there or jump back (or simply return with FE) to the original event code, whatever the situation calls for. Smaller events wouldn't matter, just end it and have the extra bytes left over become free space then. There's no pointers or anything for event code that need updating, so no worries there.