Personally, I would never store my boat simply for the convenience factor (or lack thereof). Also, unles you get a storage unit that is enclosed and only YOU have access to it (which can can be pretty pricey per month... $100+) your stuff may get stolen anyway.
As long as your boat is at home, if you aren't interested in taking your speakers in and out, you can get some covers for them which will help you NOT advertise that you have them to passers by. Go to www.screaminsacs.com
. They have some you can buy and are really nice. We just bought some. They are local too (Sacramento). Ask for Dan and tell him Renee and Tate sent you.
On a more expensive note, you can install an alarm on your boat if you think it will be outside indefinately. Check out this thread for details: http://www.wakeworld.com/MB/Discus/messages/3183/220903.html
As far as neigbor complaints... depending on where you live and if you have CC&R's (Gold River) you might be ok. Although if someone complains, point out all the RV's in the neigborhood and tell them to go to H@LL