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I am sure I did not give enough info on the other players in the game etc

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You didn't even mention what the game was!
1. As well as semi-bluffing out the chaff, if enough people call then your bet is also profitable (assuming if you hit your hand you win but meh) so it has a lot going for it.
2. Middle position is a vague term. How many players are seeing your flops?
3. Yes

The pot odds are really important, as are implied odds if you're playing a big-bet game (ie not limit)
Draws play best in late position with caveats.
One easy way to demonstrate this:
No-limit holdem. Say 6-max. You raise T9s on the button bb calls. You flop a fourflush 1 overcard on table.
BB bets $x. What do you do?
BB checks. What do you do?
No-limit holdem. Say 6-max. You raise T9s in the cutoff button calls. You flop a fourflush 1 overcard on table.
What do you do?

Having to act first puts you at a disadvantage against good opposition. At lower stakes opponents do not take advantage of it often enough but after a while you can feel how much better the button situation is than the cutoff one. Having to act first after the flop is a vulnerable position.
In limit the same principle applies but the pressure that can be applied positionally is limited to one small bet and maybe two big ones.