What is any good Terran tactic to play on maps that prevent early rush?
Important thing is intelligence... should I spent minerals to improve command center for that? Or it is better to build Barrack to fly around for that purpose?
Can't rush? Expand!
Terran are the most defensive race in the game, and the best at repelling early aggression due to their ability to 'wall off'. Because supply depots can be raised and lowered like a draw bridge, Terran can create a wall at their ramp that can only be passed by their units. In addition, by walling off the top of your ramp the enemy is forced to post a unit at the top of the ramp just for vision to return fire on your units. This further increases the defenders advantage making it harder for them to retreat and providing a natural choke on their units.
Terran walls are the most effective early game rush prevention in the game, but that doesn't mean they are invincible. Good game awareness, unit mixture, and repairing the wall can often make the difference between a win and a loss when your wall is hit hard.
A pictures worth a 1,000 words :)
Now that you have safely gained access to the mid-game, as you mentioned the next concern is intelligence.
By combining good scouting with a solid defense your chances of losing to an early rush is significantly diminished.
The Early Expand
Because Terran is naturally such a resilient and defensive race, they often have the ability to defend against a much larger opposing force. This leads to a powerful early game expand (generally 1 or 2 Barracks building marines into an expansion). See the image below as a bunker and a tank holds off a much larger force.
By combining the above concepts (walling + scouting) with Terran's natural defensive properties (free bunkers) you can often gain an early advantage and still survive if your opponent attempts to put on early aggression.
Flying over the base with a Rax is more economy efficient and allows you to see more of his base...
But this economy advantage is only the case when you choose to go Orbital Command and M.U.L.E.
I would use the extra scans and supply only in emergency cases (supply blocked due to wall taken down, scan because you don't have anything against cloak), but if you have map control you wouldn't need it as you would see your enemy coming so you can get your supply, detection and defense up.
As a Terran if you upgrade your command center for scan and M.U.L.E, only scan early if it is impossible for you to scout with a marine or a SCV(blocked entrance for example). M.U.L.E is a really big economic advantage that shouldn't be wasted, especially early game or if you need scan for cloaked it can lose you a game if you don't have it.
I wouldn't recommend using flying barrack early game because you might need the extra marine bumping early game especially if you find out they are doing early rushes. But for mid late game it might be the best way, otherwise mid or late game scan can be good to because you will most likely have expanded or have your mineral line saturated ( no use for M.U.L.E )
So, your question seems to be:
Dealing With Large Maps
I think that Terran suffers less than Zerg gains on these maps, so a lot of your concern here is ZvT. If we look at Scrap Station or Lost Temple, these long rush distances don't really hamper Terran play as much as they help more Macro based play which is so common amongst Zerg.
You have a couple choices here, since you know its likely your opponent will utilize the map size for more Macro oriented play you can either follow up with your own Macro play (1 Rax Expand); provide slightly delayed rush with pressure (2 Rax play); or you can actually go in the opposite direction and become very aggressive (bunker play). Let's examine these in depth
Many Terran players have been favoring the 1 Rax, Expand as a nice opening against Macro oriented players. This sets the Terran up on 2 Base very early which can lead to a very powerful Terran player as they'll have the resources for heavy Mech play. This is a very scary position to be in for most players and even if they are maintaining equal bases, having a Terran move to two early can put people in a poor mid game.
Because many people counter fast expansions with pressure, its not infrequent to get on one of these maps with a long rush distance and then find yourself under a lot of early pressure as your opponent tries to deny your expansion. The 2 Rax expand provides you with a significant early fighting force (almost always pure marine) and allows you to take and hold that expansion. On maps which are large, but not huge (think Xel'Naga Caverns or Jungle Basin), going 2 Rax before Expanding is usually the safer choice as it will allow you to shut down any early pressure by your opponent and even pressure him strongly. PainUser is a huge fan of these builds.
If a Terran wants to be aggressive on a map with a long rush distance the Bunker is a very cost effective way to do this. Sending across 1 or 2 early Marines is usually not sufficient for a rush as the long distance delays them too long, but add in a Bunker and very good way to boost that early rushing force and has the added benefit of being able to salvage the Bunker after its done being used. The key point here is that you're not trying to end the game with the rush (you won't have the units for that), but to deny the early expansion by your opponent. SlayerS_Boxer frequently runs this build.
Scouting as Terran
Your first step should usually be getting an SCV into their base (usually after your first supply depot). From there you can keep it alive and good a good idea of their starting build (Fast Expo, Early Gas, etc).
Early Game, it is frequently worth it to send a Marine (or Reaper) up to the front of their base to get an idea of unit composition and possible build. While a Mid-Game opponent might have the forces to prevent you from gaining information, an Early Game opponent will either have to over build units to stop you (drawing resources away from economy), or be already rushing (which is good information regardless).
You should almost always go for an Orbital Command because the value of the MULE/Scan cannot be overrated (that is a mild exaggeration for those who can't tell). Though many people will point out that a Scan costs you more minerals than losing a Barracks. From that perspective using the Barracks is frequently a better choice in the Mid Game (when you can afford the build time) while a Scan may be more necessary in the Early Game.
Beyond the Mid Game, you're starting to look at using Medivacs, Viking, Banshee to scout the opponents base, or relying on Scans off of 2-3 Orbital Command centers (representing 1-2 expansions).