Hi, welcome to Cardschat.
Good SNG Strategy consists almost exclusively of tight play early on. While it is true that in the first few levels there is slightly more room to maneuver post-flop, I would still not recommend it. Small ball requires very very good hand-reading abilities, and the consequences for being wrong and losing a part of your stack are far greater than the benefits of increasing your stack by a little before the blinds begin to escalate. So you can play a few more hands, but not a ton.
If you're looking to widen your pre-flop hand range, I'd suggest pocket pairs and good suited connectors, like T9s. These types of hands are good because they flop hands with good equity, like sets, big two pairs, or pairs with good draws, that you can feel comfortable stacking with. When you try to play like Daniel Negreanu, however, and limp in with 75o from middle position, you are going to flop a lot of marginal hands that you won't be able to play for your whole stack, and it's not worth the risk, cause your tournament equity won't increase a whole lot when you try to make great reads or get to cheap showdowns.
The importance of position and implied odds
cannot be overstated either. Without those two things, it won't be profitable to play those big play hands, e.g. small pairs and stuff. You want probably ~20:1 implied odds, and that's when you are in position. Simply put, without those odds, you won't make enough money in the long run. I say those are the odds you need for when you are in position because it's a little easier to extract value when you're in position than when you're out of position. If you're out of position you need even greater implied odds, more than 25:1 I'd say. So if you're at 5/10 blind levels and someone raises to 30, and the effective stacks are 1500, you have 30:1 to implied odds. However, if blinds are 15/30 with the same effective stacks, and someone raises to 90, you're now getting less than 20:1 implied odds, so it's not worth playing the "implied odds" type hands.