Taiwan Nationals 2014: part 5 -- Semifinal over (and some advice needed!)

The semifinal tournament concluded today. Got 6th place of ~60 players with 7 points of 11. 

While it is enough to qualify me to the final group of 12, there are aspects of my play that needs improvement. And damn quickly. The finals are in a week.

In each game I lost, I had an overwhelming, if not a won position. 

Against the tournament winner, Austin, the computer evaluates my position at +8, with 7-8 minutes to go on the clock (+30 secs increment per move). I lost.

Against the highest rated player, Alex, the computer evaluates my attack as +7, with 9 minutes left. I lost.

 And my third loss was against Sammy, where I win a piece early on (Houdini puts the position at -4.07 in my favour). Here I had almost 11 minutes left.

None of those evaluations are due to some deep tactic, they are sustained in quiet positions several moves in a row. I lost all those games. Mostly by playing the same way I got the advantage, doing proper threat checks, ending up in time trouble and then losing to tactics.

So my cry for help is: How to do a proper threat check, aginst a tacically able opponent, in well under 30 seconds? It seems that I need 1-2 minutes per move to do that. And that way I will run out of time, and eventually become the victim of surprise tactics.

Just as an example how I lost the game vs Sammy (see if you see the threats in 30 seconds!):