You can be as obsessive or relaxed as you wish and still end up with usable compost so don't worry too much about layering. My mum has composted since the 70's and laughs at all the detailed instructions given out on what you must and must not do now that it is fashionable.
You do need to have a mix of green (eg garden and kitchen waste) and brown (dry eg paper, cardboard, dry leaves etc) but don't get too worried about proportions or the size of layers - if you are putting stuff in on a daily basis as the result of cooking/gardening and reading the paper - the layers will probably be fairly even anyway. Just remember that it it goes slimy and smelly you need more brown. As you have said if you are planning to regularly turn is the layers will all get mixed up anyway.
Turning it will make it compost quicker but is not essential if you are happy (and have room to wait). The biggest factor in getting compost wuickly is the size of your heap/bin - 1m x1m - is the minimum to have a 'hot' heap. If smaller and not turned you may have to wait 12 months before you have usable compost but it will keep reducing in size so there will be room for you to keep adding your kitchen waste. When I was working fulltime we just kept adding stuff to the bin and the only turn it got was the odd stir at the top and then when we emptied it once a year to get the fully composted stuff from the bottom.
You can compost any veg or fruit waste - bananas and citrus peel are great (it's worms in wormeries that don't like too much citrus). And yes add manure by all means but make sure its not too fresh (as that can get quite a time to become usable on your garden). A spadeful of garden soil can help add bacteria/worms etc especially if your compost bin is not sitting on the ground (eg on soil not a patio/drive).
The benefit of compost is not really the nutrients but the fact it adds organic matter to your soil which is essential if it is too have a good structure which retains nutrients and allows plants to obtain the nutrients and water it needs