a few ideas
First, there's the issue of pinning the keel down or not. In general, if in shallow waters, with a chance of bottoming out, most people opt not to. If you're in heavy chop or near motorboats, you may want to lockdown due to the negative effects of inertia (ie, keel bashing)- in which case you won't be adjusting anything. Also, some say that a swing keel cannot be counted on to self-right a boat if it's not pinned down. If you're in heavy stuff, it's less obnoxious and safer. As far as playing the keel on different points of sail: keep it fully lowered when pointing; fully retracted on a run (less wetted area, and the boat is already sitting relatively flat). Just be on your toes for a broach if you catch a puff. As mentioned about self-righting, you are vulnerable in this position. When reaching, you can play with the keel partially retracted if you need to fine tune the helm balance- though you'd better check your rig balance first (mostly mast rake in relation to sailplan).
