Hiya, congratulations on the new babies! Will look forward to the pics!
We have a 9 week old bearded dragon and I know where you are coming on from the whole ammount of conflicting advice you get when you are researching one!
I would really try to remove the crickets as the bearded dragon won't hunt at night and although it won't cause major problems I would have thought, you do hear horror stories about crickets and as they are babies I would very much try to remove them, just in case!
A 100w should be absolutely fine, in fact we have had a 100w in ours and just downgraded to the 60w as the heat given off by the 100w went up too quickly and as we measure the basking spot was getting up to 60 degrees centigrade before cooling back down in the mornings. The 60 seems to be much better at the moment - slower rise in the morning but maintaining temps during the day - although we are still doing tests to see what the cooler end of the viv measures in temp. (we have a 4 ft viv too).
A digital thermometer is a must - the dial ones are not too accurate and can be up to 10degrees out. You can buy cheap ones on ebay which will do the job fine - we brought one with 2 sensors on so we could measure the basking spot and the cooler end - it was less than £10.
You do need to measure the basking spot ideally getting a temp of 110 -115 degrees fahrheit for a baby.
We have been told not to spray our bearded as most of the water they need they will get through their food. There is a good sticky in the lizard forum about this. Although it is a contriversial (sp!) subject and there will be lots of different advice! :p
Hope this helps and I haven't confused you even more!