Glad to help out. Again, all opinions are just that, opinion, unless I site a source.
As far as salary/compesation goes, here is something to think about. Where do you want to live and practice? That 200K will go alot further in a rural setting or in the affordable South. Demographically, physicians as a whole are compensated better in the Southeast US. This is mainly due to a lower level of HMO prevalence and a greater demand for most specialties. Also pick a place where malpratice insurance is available to your specialty at a more reasonalble price, and possibly where there has been some statewide malpractice reform. Finally pick a place you want to live and where you and your family will be happy. In medicine and in general, lots of money but hating getting up to go to work everyday will get old real quick.
Your question was which specialties will allow you to work mostly with kids and get paid well. As I alluded to earlier, pediatric surgical subspecialties get paid the real jack. But these require you do a surgical residency then subspecialize. IE general surg 5 years --> peds fellowship 2 years = $500K
Urology/ENT 5 years + 2 years fellowship = $3-500K.
The other question is what pediatric specialties can make money. As a general pediatician the average pay is about $140-160K, working a reasonable 4.5 days per week schedule. I expect this to stay about the same. You asked about changes in general peds and reimbursements. Most insurance plans and Medicaid do not reimburse well for kids or preventative health (ie, if you want to make $$$ find a good billable procedure - GI scopes, surgery, PE tubes, etc.). What this means is that whereas the IM doc sees 3-4 pts per hour, the Peds guy must see 4-5 per hour to make the same cash. The problem in gen peds right now is that more and more parents are wanting more of your time to talk about social, behavioural and nutritional issues, shots and autism, etc, ie "non-medicine" things. So they take more time for the same billing. We as pediatricians are notoriously bad billers. We feel "bad" for charging for more than one code. The sucessfull peds practices I alluded to earlier have a designatred billing person whose job it is to maximize billing. So, when at the end of the acute "check my ear" 5 min visit, mom asks about constipation or sleep habits, the good doc will say " I am really busy today, but would love for you to come back next week to talk about just that for a full 15 minutes" abd bill for BOTH visits. Anyway, sorry, I digress. So, it is possible to make $200-250K as a general peds person if you are a partner of a well run practice who uses good billing people, and who might use a good NP/PA for patient education, and who has an in office lab/xray (you get a portion of the bill for every test you order).
Peds subspecialists tend to be required to live in proximity to a Childrens Hospital or in a city large enough to support a private practice. The best paid is hands down private Neonatology - all intensive care billing and a pretty good life if set up right. The private guys where I am from in south Louisiana are making $400-600K per year. But you have to like Neo, which is another whole discussion. Next is prob Allergy/Immuno - again, they have the good old allergy testing and shots for procedures to bill for. Most other peds subspecialists work in the Children's Hospital/academic world and live in the $150 - 250K range.
Again, talking about money and compensation is NOT crass. It is realistic. We all want to be paid well for our time and education. BUT, making life decisions based solely on money will ultimately leave you unhappy. Live life to the fullest, have a family and spend time with them, travel, and enjoy what you do for a living. Those are the real things I like about medicine - if you set things up correctly, you can do all those things.