1) Won't sync
3) Hierarchy View > Mission > Game Data > Palletes or something like that
4) What's wrong with the weapons? The weapons in the globals are the ones that appear when you do cheat_all_weapons. You need to manually change the netgame equipment in the scenario
5) Mediafire's fine. If they think it's a virus, then that's their problem.

1) You could theoretically get it to sync, but not well
3) Yes
4) Create a new netgame equipment file in guerilla, specifying the fields (weight being the percent of the time that you want this weapon to spawn, 100 for a netgame equipment with just one weapon as probably will be your case. 50 if you have two weapons in there, 25 for four, or 25 for one and 75 for the other if you want the other one to spawn significantly more times than the first one.)

for your custom weapons just do the same as gamma mentioned.also make sure the custom weapon your using has a item_collection file.if it is missing this item_collection file then just make one in guerilla.whether or not thats the same with reskinned weapons im not to sure.

Sounds like you have a room with a floor, and its walls are angled at 45 deg (150 from the floor, if the floor is set assumed to be 0). You want the tunnel to cleanly cut through the angled wall to connect with the floor at a 180 deg (0 deg), similar to the way the doors in 343 Guilty Spark connect to the minor tunnels throughout the level (floor, 45 deg wall out, vertical wall, then 45 deg angle wall back in, and the doors match nicely with all)...I know this is a horrible way to be describing this...if you have a detailed picture of your problem area, I can better relate here.

Anyways, assuming my description above is relatively correct, here's what you do:

Make your tunnel the EXACT way you want it, but make it SEPARATELY from the room you want to attach it to. Make said room EXACTLY the way you want it to (at least the wall you plan on connecting the tunnel to). Once both sections are done to your satisfaction, take your tunnel entrance and make it longer (take all the vertices that compose the doorway and move them out further, effectively making your tunnel longer).

Now, move your entire tunnel into the position you want it in, making sure those vertices you just moved outwards are well inside your room. Your tunnel entrance area should be intersecting your room's angled wall. What you are going to do is merge your room and tunnel together; this will create new vertices and faces wherever your tunnel and room geometry intersect. I had you move the vertices outwards so you could easily see them, because they represent the 'extra' geometry you will delete.

So, let's say your room is 10m long, 12m wide, and your tunnel is 2m wide. You place one side of the tunnel 4m in on the 12m wall, the other end being 6m from the other side of the 12m wall. Those vertices that were moved stick into the room, and look like crap. But if your tunnel is where you want it, then here's how you tidy this up:

Select your room, go to the create tab (in gmax and 3ds), select Compound Objects from the drop down menu, and click Boolean. Then in the options area, click 'Pick Operand B'. Select your tunnel as Operand B, and further down in the Boolean options, select 'Union' as the method of joining. Now the two objects (tunnel and room) are one; delete the faces that extend into the room that were once part of the tunnel (these are the vertices you moved outwards. Now you can see them easier, and thus delete them easier). Next, delete the faces that are part of the 12m wall that cover your tunnel. If done correctly, your tunnel and room should now be perfectly merged with no changes in angle or geometry.

Let me know if you have questions, or PM me if you desire.