ok,
bilateral breathing just means alternate breathing (3's, 5's, 7's etc - as an aside, good drill for lung and -i think- anaerobic training is to do a lenght breath every 3, a length every 5, a length every 7, a length every 9, then back down, 7, 5, 3. etc.) and yes, freestyle, you'll find your own rhythm for breathing backstroke, fly i breathe every 3, breastroke every 1 or 2 depending on whether i'm working hard or not. Whatever is comfortably for you -like running.
As far as shins go, i guess shin splints could be aggravated by 'aggresive' kick, but if you're just kicking a little to maintain body position i can't think any harm would come from it, the burn i talk about is mostly due (i think) to the lack of muscle on and around the shin - calf is much stronger, but isn't really utilised as much due to the nature of the movement. If you have no problems with your shins then don't worry about it, the burn feels like any other muscle 'burn' when in the gym etc. If you have trouble with shins then swim with a pull buoy between your legs untill they're better.
as far as freestyle kick goes, well, most of the work from the kick is underwater -if you waste energy with half your kick above water, then it isn't propelling you anywhere. However splash is inevitable and doesn't mean you're doing it wrong. When you next get the chance watch some swimming races on telly, helluva lot of splash in the sprints going on, and a constant steady splash from kick going on in the longer distance races where there is less of a sprint element. If you kick fast and hard there'll be a lot more splash than if you do deeper slower kicks (which are better for toning i think -not that it's worked!!)
