Limp with small pp

[Altreg]

Ok this situation happens with me cpl times in online trny's
I got about 40bb in Stars rebuy bb600,limp in EP with pocket 7s or 9s,Average stack player(like 25bb) raise 3bb from CO,now do i call this HU against average oposition(dont have any special read on hem)?

Last time i got 7s in this situation and i reraised hem allin
trying to represent monster,he obvios cold-calls with A/10o

What is the best line,just flat call and play hem postflop?

Another situation-middle stages of online rebuy trny,i got like 18bb(got cpl bad beats earlyer and one by this plaeyr)
I limp with K/5s UTG+1 same guy(he has about 40bb& been playing loose)raises 3bb from office,now im trying to re-steel and push allin(again representing monster)he cold-calls with A/9o

Am i just outplaeyd myself on this one ,giving hem too much credit?