I'm not sure if it's the same thing, but in my pub league, we do allow a "dribble" bet. I.E. Stack in hand, chips are dropped one at a time, provided that they are dropped at a reasonably quick rate. If there is any sort of extra delay between chips, the bet stops before that last chip. Similarly, if the hand makes any sort of backwards motion, no more chips.
Straddles are additional blinds. Yeah, in a 1/2 game, if someone makes a min-raise to 4, the next min-reraise is 6. However, a straddle of 4 makes the min-raise 8 and a min-reraise to 12.
Similarly, a double straddle to 8 makes a min-raise 16 and a min-reraise 24.
And, yeah, post flop the minimum is back to the regular big blind amount.
Of course min-raises and min-bets rarely happen, but it's good to know the rules.
Yes, the straddler can check if there were no raises. It's like another blind - he has the option to raise, but not required to do so.