short answer to your first question - on all but the hottest of summer days, you'll encounter a sea breeze from the south on your way home in the afternoons, its a function of the temperature and air pressure over land vs. over the bay/bass straight.
As for your second question, as much as 80% of your energy goes into propelling your body through the wind, the lower profile you have into the wind, the less energy is wasted. if you ride a mountain bike, there isnt a whole lot you can do with your riding position to get lower, a set of bar ends might get you a little more extended and therefore a little lower, tighter fitting clothes will obviously be more aerodynamic, and slick tyres will reduce rolling resistance. If you ride a road bike its much more simple, use the drops, you may find it takes a bit of getting used to riding in that position, but thats what they're designed for. The best and easiest method to beat a headwind is to draft other riders/traffic, ride out into traffic as far as it is safe to take the biggest advantage, and consider trucks and busses a blessing, they'll offer the best tow. If you do draft other riders, you need to get right on their back wheel, so stay alert, and dont forget to return the favour, if its one thing i hate its lazy people sitting on my wheel who arent willing to take their turn.
Hope this helps, id like to say that as you get fitter it gets easier, but wind resistance just gets bigger as you get faster. Your best bet is to view the wind like its a training aid, its helping you to get fitter by making the ride harder, remember the glass is never half empty, its only half full