Depends what race you are playing against. TvT is the same here as its been on most other maps. I treat this map like most others, with the one exception that I try to go more aggressive because I feel that expanding here is more difficult because the expo is so open to an aggressive player. I whip up some air units, keep them contained no matter what race they are and then I just try to get creative with tanks/ravens/tech/reapers. Maybe if you could tell us some more specific problems you are having, my responses could be more helpful
I haven't played a single game yet but I've seen countless replays where the Terran player will go fast reapers/hellions to do some significant economy damage. Not sure how viable it actually is in the real game.
Well, all I know is that Terran is infamous for "floating to the gold" on that map. That is, at the very start they lift off their command center, fly it to the nearest gold mineral expo, land it there and start mining like normal. This allows for some crazy mineral income on one base, usually they take advantage of that by going 4 barracks mass marines and ending the game quickly.
Always keep your army on higher ground near/relatively close to your base and expansion if you aren't attacking and just sitting tight. I like to expand in two places (my natural and one farther away and hidden) when I can do it. A gold expansion is fine too. Reaper harass is pretty awesome because there's a lot of edges at my opponent's main I can abuse. Marauders with the Concussive Shell upgrade is amazing when they're camping up on a ledge. You can slam down with a lot of free hits and usually pick off a few of their units. Also, make sure to figure out where your opponent is and hold the Xel'naga tower closest to their base.