strategy for live weekly pub tourny

[pearljem]

Just looking for some strategy tips for playing my weekly pub tourny.The field is normally between 25 and 30 players.15min blind levels with a starting stack of 5000 and one rebuy or top up at half time.Top 3 get paid.I have played 13 of these this year and ft 9 of them but have only cashed once which i won.It is full of loose passive and tight passive players which is why i ft so much,but it becomes such a crabshoot at the end.I usually start off tight and look to get paid on my big hands.Is this ok or should i be playin loose early on to try get a big stack in order to survive the blinds at ft?I never allow myself to get blinded out but when i reach the final table i usually am around 25000 or 30000 and still only have 5 or 6 bb.Should i loosen up more in mid stages?also should i be thinking in terms of m or bb as there are no antes?any comments appreciated,thanks