Did you ask your provider about the temperament of the queens you ordered? His bees in general? I often hear about Buckfast or Russians, or other specific lines of bees that are just TOO aggressive.. I have found that queens from the same genetics but different lines can be very different in temperament. I also have some difficulty believing any line is "pure" due the the nature of mating queens.
I mow and weed eat around my hives with no gear, and I usually work the hives with no gear, because I work pretty hard to remove aggressiveness. You can do it too. I have 42 hives at this moment.
Splitting this time of year depends on where you live and the weather for the rest of the summer and fall. If you have a moderate flow the bees will be able to rebuild, feeding them will be helpful, and maybe mandatory if you do not have a good flow between now and winter.
I would concentrate on the hive or hives you have, do the best you can for them, and make plans to increase in the spring when they will have the best chance if the weather does not cooperate.
If you have 4 minutes you need to waste go to the link, watch the vid at the bottom... mowing around my hives.
http://outyard.weebly.com/honeybee-care.html