I am sorry that I did not see your question when it was originally posted.
As far as pre-flop raises are concerned, you have to understand that I only play in tournaments where the blinds become proressively larger, hence the multiples of the big blind used for pre-flop raises will vary according to the situation in the tournament, the size of the blinds, the size of the stacks at the table, and in particular the status of the person in the big blind at that time and their tendency (if known) to call preflop raises or fold.
At the very start of a tournament when the blinds are 20/40, if I have a promising hand I would probably raise to at least 4 big blinds with the expectation that I will get at least three callers since most players on replay poker are devout followers of the limp-call strategy. If you are getting three or four callers every time you raise pre flop, you only have to hit a good flop once out of every three times to win good sized pots.
I don’t believe in limping pre-flop with any two cards, which is the strategy that most of my opponents use. Sure you will win some lucky pots that way, but you will also lose huge pots when the board pairs and your two pairs of something like queens and fours are beaten by somebody else on a king queen 4 flop.
As far as the middle pairs go, I would evaluate how to play them depending on the situation and the stage of the tournament. In the early going when the stacks are large relative to the blinds, there is not a lot of point putting your stack at risk trying to win the blinds pre-flop, but if you are able to see a flop cheaply you may hit a monster and take down a super aggressive opponent.
In the later stages of tournaments you want to put in a large enough raise to deter opponents from calling unless they have premium hands, so you may often take down the pot without seeing a flop. On the other hand, if you raise with a pair of eights, and you are called in the blinds, then your pocket pair is probably a slight favorite against two over cards if it goes to the river, but is a 2 to 1 favorite to be ahead at the flop. The biggest danger of course is that you are up against an over pair.
Anyway, if you are small stacked, then you have little choice but to shove with your pair of 8s, but if you are large stacked, you might be able to check in from the blinds, and then if you hit a set, you can ambush your opponent on a later street and hopefully stack him when he makes two pairs or a smaller set.
In tournaments everything has to do with the size of your stack. If you have a large stack you can easily afford to let pots go if in doubt, and wait for a better spot, but if you are small stacked you have little choice but to pick your spot and go for it.
As far as winning a huge part with suited connectors, in MTTs you always have to be aware of the relative stack sizes. If you are now the table leader, you have more to lose than to win, but on the other hand there is little pressure on you to play hands, so you can wait for good cards.
One of the biggest mistakes people make is calling raises without having good odds. I will often play hands like Queen 10 and King Jack suited if there are 3 or 4 opponents, because if these hands make top pair or better, or flop a straight draw, they can be very powerful. On the other hand if somebody smacks in a huge raise or reraise pre-flop, it is probably better to fold, because these hands are easily dominated by other hands like ace-king, ace-queen, and if you are up against an opponent one-on-one, then you don’t really have the odds to call.
It is always best to be the first person to enter the pot with a raise, because there is always the chance that you will win the pot unopposed, but if you call with a hand that needs to see a flop and that is likely to be starting from behind, the odds will usually not be in your favor.
Then again, if you are in the small blind, and there are two limpers already, then you can probably limp in, and if the big blind does not raise, then you will be potentially getting seven to one on your money, so you can really afford open up your range. On the other hand, if it is folded to you in the SB, it is usually best to fold unless you have a very strong hand, because you will be playing out position, and if you do raise from that position, then you need to be prepared to call if the BB shoves back at you.
I hope this helps a bit.