I recommend playing 1v1 and 2v2 with no rules. Anything such as no T3 artillery/no nukes..etc are just stupid rules that encourage people to defend heavily and get away with having a poor economy versus other players. If im able to get 2/3 T3 artillery up, before the other players, they either have poor resource use, havent scouted my base or have no offensive units to take them down. Exactly the same with nukes, if you scout a base and see the silo, either take it out or build the defence ASAP.
Out of interest do people tend to pay annihilation or assassination..etc?