Hi again
as for the extending awake times, sometimes even though they seem sleepy after 2 hours for instance, you can still increase the awake time by say 15 mins. it is not too much to make them overtired, but just enough to make them nice and sleepy for nap. i know with my dd, she still shows sleepy signs sometimes as early as 1 or 1.5 hours after getting up, but if i put her down then, she will just play or scream. i think sometimes her yawning/rubbing eyes is just telling me she is bored and needs a new activity, not a nap. but that is just my lo. yours may be different.
also, about your dh putting baby down...i also did all the putting down until dd was about 4 or 5 months. then dh wanted to start helping. i was SO nervous, so for the first few times, we put her down together. he actually laid her down, but i was right there too. i think this was more for my peace of mind than for gianna. i don't think she cared. so to ease your mind, you may try doing it together for a while until you are confident he can handle it.
hope some of this helps...or at least makes sense!
ps-hi meg's mom.