I'm an insurance agent in PA (but also licensed to do business in TX). The .02 short version is that a home/tenant/etc. (personal policy) is not written to cover a large amount of tools. Assuming you are only using them for personal use, your personal policy should allow coverage, but only to a small limit (which will be specifically outlined in your policy) to something in the vacinity of $1,500. This is a SUB-limit of your personal property limit, much like computers or guns, etc. If you have a limit of $75,000 of personal property, you still only have the $1,500 sub-limit for tools.
If the tools are used in any professional manner, then you need to cover them on a commercial policy as they are then spefically excluded from your personal policy.
An Inland Marine policy is generally going to be the best way to cover tools, but depending on your specific situation, there may be other and cheaper ways to get them covered.
If you are doing ANY work on vehicles you don't own, then you should have a garagekeepers policy to protect you from liability issues. It may be cost prohibative for you, but would be the correct thing to do. (The price for a small, lower limit policy will probably run you $1,000-1,500 a year and include likely include tools.)
If you are renting space from someone else, even a friend, you can be liable for damages you cause, such as if you catch the building on fire. Again, it goes back to whether you are doing business professionally or personally, but it isn't great idea to rent space without having your legal liability taken care of.
I can elaborate as much as you would like but don't want to throw too much at you. It would also be easier to have more specifics on your situation. I'm happy to answer your questions if you have any.