Alice was an incredibly difficult fight, even on Explorer (though as I've said various times previously, I'm an adventurer, not a tactician). I think I eventually dealt with her when I was about a level above but it was still tricky.
Dunno about the last fight, but the doctor is level 20, and can become quite awkward if you're ill-prepared.
Probably quite obvious when you do it, but you really need to one-shot him before he has a chance to turn. Otherwise it's much more... well, "tactical".
The end battle was just too protracted for me, whatever level it was, but I often say that about video games with end battles and frequently fail to complete them as a result.
