Limit switches are essential in my view... and they are much more useful than just to prevent something going off the rails so-to-speak. Having said that 30p spent on a micro-switch can save you thousands of pounds in damages.. which is worth it in itself. The day your gantry falls off the end of your table will be the day you decide should have used a limit switch....

Also each time you set up for a job you will need to have a referenced position in relation to the stock... Same goes with tool-changing ... or setting up for a different job..... this is soooo much easier when you can ref the tool position in relation to the table overall. You can only really do this using switches... Also, if there is any kind of problem with the cut and you have to re-start the job.. you will need to do so from a known position.

You can just ref off the stock each time.. and on a small machine sat next to the controller this might be an acceptable way to work for you... but for peace of mind and ease of use I'd recommend home and limit switch on each axis....