1) There is absolutely a huge edge to be had playing live tournaments, even for buy ins in the $1k - $5k range. If you are playing outside of Vegas it is very common to end up at a table where at least half the table are "recreational" (i.e. players who are bad and are likely to make large mistakes).
2) The downside to playing live tournaments is that it is difficult to get reasonable volume in and the variance can be brutal. It is not that unlikely to go on a 20+ buy in downswing even with a decent edge.
3) Having an income source not tied to poker is huge and allows you to not have to be conservative with bankroll management. If you're pulling in mid 6 figures from a day job you don't have to worry about selling action or going down in stakes when you go on a downswing because you can always supplement the bankroll with your income. This, obviously, can be taken too far, but you don't have to be as worried about the variance from shot taking a higher buy in tournament where you know you have an edge like the $10k WSOP Main Event which is by far the softest $10k that exists.
As the saying goes, being a professional gambler is the hardest way to make an easy living.