How many regular research stations are you allowed to build on the board during the Team Play?
You can have all 6 normal research stations on the board. The team research stations are *in addition* to the normal ones. See ITL rules, page 6.
are you only allowed to cure at your team station?
No. You can cure at the normal or your own research stations, but not at any of your opponents' team research stations. See ITL rules, page 7.