First, the Commander of the squad dictates what the squad is currently doing. If he's asleep the rest of the squad will be around him, if he decides to go eat, they follow. That being said, if your dwarves are ending up on the wrong side of whatever you want them to patrol to, just move hte patrol point alittle ways back in teh direction you want to shift them.
Depending on what you want them to accomplish you may want to give them backpacks and waterskins. (note, for any wrestling unit do not give them backpacks. As they wrestle they'll toss out their food on the floor which will cause miasma and tick off nearby dwarves, also food that is in a backpack is claimed by the owner of the backpack so other dwarves will ignore it.)
By investing in your food preparation (i have... well had... a ledgendary chef who made masterwork prepared meals) you can extend the duration of time they can spend on duty. with the waterskin they will drink water, but will not get an unhappy thought until after a while, but they dont get a happy thought for booze. Sleeping on the ground causes unhappy thoughts but if you manage it right you can keep them on patrol for a good while. Make sur ethat when you take them off duty that you tell them to not carry water so they'll drink booze.
In regards to your marksdwarves problem
A) do you have more than 25 bone bolts that aren't forbidden?
B) Are they off duty?
C) Are they not socializing?
Marksdwarves are notorious about shluffing off training. my suggestion would be to retain any prisoners you capture, strip them of their gear, and use them as targets for your dwarves to practice on. You are garrunteed that the marksdwarves will shoot them, and you can dictate when and how they do it.