Safezones are extremely large (larger than most game worlds on a 2D view, nevermind its 3D space) and it has been stated that camping them (attempting to..), if that is even possible to do with a large group, is against rules and some sort of action would be taken. In order to camp a safezone - with them as large as they are - I would guess a full faction blockade would likely be required just to spot things trying to leave it, never mind react to them.
If people want to use inefficient ways to mess with you, let them, is my personal opinion. Ships are prohibitively expensive projectiles when compared to just shooting you with a missile, torpedo, or one of the various guns.
I will also mention, you can do a lot of mining of asteroids and station jobs before ever leaving a safezone. There are multiple safezones and spawns. If some how, an entire faction decides to be a dick, and some how, nothing is done about it, rest assured you can just spawn somewhere else and ignore them.
As far as differences in cargo theft, ship theft, and homicide, there is very little at the moment, though expect that to change. AFAIK right now you cant permanantly steal a ship as the ownership is only able to be transferred by its owner, so you can only joyride a ship at the moment. Homicide... Well they respawn a few seconds later at one of their other bodies or stations. Starbase isnt so much a 'game' as a very good tech demo at the current stage (that isnt anything against it, I am just stating its early days and I have high hopes and expectations for its future), and this is a system that I am sure hasnt even been fully worked out internally at FrostByte, much less implemented, so you can rest easy.
As always, anyone with Closed Alpha access will have to verify what I have said as some information may be out of date.