nice! (add to OP?)
forward spawn and lowered times are a good start, they were definitely necessary
edit: i guess you decompiled the map and went from there? i'm getting graphical glitches not present in stock mountainlab.
the room behind the window is visible:
http://i.imgur.com/gLNmcOd.jpg
taking one step back, it just disappears:
http://i.imgur.com/If5b8os.jpg
the same is happening from this point:
http://i.imgur.com/q0fupSC.jpg
after taking a step back:
http://i.imgur.com/P2D3gfj.jpg
also, there are (at least) two sets of stars that are not bulletblocked or playerclipped.
though i suggest you just go around the whole map, bulletblocking all the stairs.
a couple of sets are bulletblocked already, but most are just playerclipped.
same goes for small steps (like the first point), they should get some bulletblock love as well.
there are also things to snag on, like door-frames. so just like with the stairs, i'd just go from beginning till end and playerclip all that stuff.