Q1: IS badspots blockparty your server?
Q2:How do I set a default mini game?
Q3:I downloaded a sniper rifle copied it into addons ticked box and it said it couldnt load the gun shell why is this?
Q4:can you give me a link to a good program for making addons?

I can answer those for ya =P
1. Yes, it is.
2. The default minigame mod. Try searching.
3. Extract it into Blockland, not Blockland/Add-Ons
4. Scripting: Notepad works.
Modeling: Milkshape, Blender, and there are some others.
Mapping: Mission Editor for terrain, Torque Constructor (I think?) or some other programs for interiors.