I recommend taking a look at 2 sources of information about vaccines. The first is the excellent website that the Children's Hospital of Philidelphia has. http://www.chop.edu/service/vaccine-education-center/home...
Basically as a parent you need to decide what the risks and benefits of each vaccine are, and whether it makes sense to get them sooner or later. I found, when talking with our doctor, for example, that kids get 3 DTAP shots because that's how many are required to get something like 70% of the population to have an adaquate immune response. Now, they do this all before age 15 months not because your kid NEEDS to have that immunity at that age, but just because they see babies often in this age range and it means your kid is likely to actually get them all. As opposed to an older kid, who might slip through the cracks because we forget or they don't see them often.
Anyway, the other resource that I suggest is The Vaccine Book by William Sears. This one goes through an intelligent discussion of the risks and benefits of the vaccines and the disease that it's vaccinating against, and may be helpful for you.
As for what to prioritize right now, given the hysteria about flu this season and that my kids are in daycare, I did seasonal flu vaccine with my two kids (same age as yours). Both my kids do have all their vaccines, but I wasn't too concerned about being a bit late and/or spreading them out over a longer period of time.
FWIW we skipped the lead and hgb tests since we don't live in an old home (so no lead paint) and I just wasn't worried about hgb.