To split or not to split...

I agree with Brian based on my limited personal experience, and what I've learned in working with others. I'll also parrot something I've heard: you can have more bees or more honey. I think that I can see how that is mostly true.

I did a split in mid-May, in the middle of a good flow. The parent hive was crammed full of honey within a couple of weeks, and I needed to harvest just to open broodnest area for the new queen in the parent hive. The five nucs I made put on a lot of honey, too (which they get to keep). So, I got a lot of honey out of one hive and none from the others. Now that they are off to a good start, the splits are going into the slower flow of the summertime but they have a strong enough population to maintain themselves. Without a strong flow, feeding (syrup and patties) is likely going to be required if you want to grow splits enough to split them again.

You could wait, and make one additional split later in the season. If you have a strong late Summer/Fall flow, then maybe you'll be able to split the splits at that time, but then you'll run the risk of bringing them into winter low on stores and bees.

If you want them to raise their own maybe starting with much smaller splits would be best. Then you can evaluate the queens if you get more than enough and use the best ones when combining to make whatever number of hives that will be strong enough. If you only get just enough queens raised you can combine using them. I see no reason to be worried about pollen frames so long as they were frozen which they must have been. I've never had bees remove pollen that has been frozen and used in another hive for resources.
Don't stretch them too thin or you will be asking for more dead outs. I agree with letting them make their own queens mainly because 85% of the queens I've purchased got superceded within months. Even if they raise a couple of doo doo queens they would likely be ok for getting through the winter.
If you wanted to get fancy you could use the flow to the utmost benefit by putting together a couple of 3 frame mating nucs out of a couple of ten frame hive. Populate them with a frame of open brood (open brood probably won't cost you honey anyway because they will be house bees for a good portion of your remaining flow-theories may say it could make you extra honey because the brood you remove won't need to be fed by the donor hive) a frame of honey/pollen and a frame of drawn. With a honey flow on there isn't much danger of robbing and doing anything during a flow is much easier. You could even go so far to conserve bees as to make one of these to get a bunch of queens started then populate the 3 frame mating hive. If you still have the type of flow you say you do then you are in the best situation. I would suggest you will still get swarms. I got one yesterday and my flow is nearly petered out.
Good luck.