You could try using something like the Opal sock yarns, they contain nylon and are machine washable. Always look at the ball band and it will tell you how to wash your yarn.
It sounds as if you're weaving too tightly. When you're weaving you should initially make it very very loose and then when you've woven across the row put your hand into the sock and make a fist so that the toe is stretched as though it's on the foot. Then carefully draw up the stitches across the row so that they look like your other knitted stitches. A row of weaving should be indistinguishable from the rest of the knitting.
www.knittinghelp.com has excellent videos if you need to see it being done.
You would use unscented lotion because if you put a scented lotion in your knitting kit it could impregnate your knitting with an unwanted odour. I have a Sasha doll who was obviously kept somewhere near perfume and his hair has the smell of stale perfume. Although it's been washed many times it won't come out. Smells like that if the item is kept in an enclosed space can affect other items in the area so you need to be careful.
www.getknitted.com has a sock knitting chart giving shoe sizes and the equivalent length of sock foot to knit and you could use this information to knit your boyfriend's socks.
Yes, if you want fine socks you do have to use fine yarns and needles but it's well worth the effort! If your socks are thick and too large you're probably using thick wool and needles too large for the purpose. You really want fine sock wool and 2.5 mm knitting needles or their equivalent, or even finer depending on the sock yarn you're using.
Lucy Neatby's book Cool Socks Warm Feet is great, also Nancy Bush has written some nice sock books, any of which would help you.