Hi Rick & Deb
Many folks leave there boats and travel inland. You're not alone with those concerns.
When we leave the boat at anchor or a mooring and travel away from the boat for more than a day we do the following:
Anchor or Mooring
1. Start talking to other cruisers before you arrive at your destination and see what the rumor mill has to say about safety, break ins, etc. Try the local SSB cruiser nets, Ham nets etc. ask the long time cruisers that maybe anchored there.
2. At anchor we usually let out more scope than normal and really back down.
3. We always sit at least 24-48 hours in this location to see how the boat swings, etc.
4. Even if people say its safe we always ask friends that are close by to us to keep an eye on things. We give them our lock combo, emergency way to get a hold of us (email address or cell phone). Show them where extra rode is, spare anchor, etc.
5. If it's a mooring we usually try to dive on it if possible to inspect the connections.
6. Take the large awnings down before you leave and secure the decks.
7. We usually hang the dingy on a bridle and grab a ride ashore from someone close by.
8. The discharge for the large bilge pump is in the transom. We usually stuff a small piece of red spinnaker material with a grommet on one end. Attached to the grommet is a light line tied to the stern pushpit. If our friends see this red piece of spin material blowing around they know they need to investigate as the bilge pump has kicked on
In a marina
1. Again we try to do many of the steps from above
2. Enlist neighbors in the marina to keep an eye on things if possible
3. Hire a local boat watcher to check the lines, bilges, etc.
4. Give the marina a contact number if you have a cell phone with instructions to call collect if the need arises.
5. Same with the bilge pump flag
We have left Jacaranda a number of places in Mexico, New Zealand and Australia both on the hook and in a marina. A Mexican man in Marina Mazatlan is currently looking her after while Linda and I are in Boston for a few months. Ruben came with stellar reports so we have no concerns. Plus our neighbors report he is very attentive.
Leaving the boat at anchor in an anchorage when there are no other boats anchored would cause me some concern. Unless you know its super safe place I would not do it.
Depending how long we will be gone we usually leave the solar panels plugged in and the fridge on. If we are planning to be away from the boat for 3-4 weeks or longer we usually turn the fridge off and clean it out.
Trim: Yes I agree heavier anchoring gear would apply to anyone going cruising not only if you're leaving your boat.
Don't worry about this aspect of cruising there is enough things to be concerned with as it is. If you do your homework ahead of time you should be just fine.