When I start playing poker again a few months ago, I read Daniel Negraneu's SnG system on PokerStars which recommended 4x as the standard and its the habit I've gotten into.
I'd really be surprised if Negreanu suggested that 4x should be your
standard opening raise. He generally advocates a "small ball" style of play in tournaments. Negreanu may have been talking about certain situations that warrant the 4x raise. Do you have a link to his SNG system?
My impression is that the
standard opening raise in most online tournies these days is in the range of 2.5x - 3x and it will change as the tournament progresses. I use the term
standard loosely because, as Bwammo suggested, you should always know what you are trying to accomplish when you choose a particular bet sizing.
I think that in the situation which you outlined above, it is probably best to fold. We really don't have a read on the villain yet (nor does he have a read on us) this early in the tourney. This is a micro stakes tourney and he could be the type of player who likes to try to double up early with any two cards, but he could just as likely have TT+ and feel that you may be enough of a gambler to call his shove.