Hello Jacksparrow, and welcome to Seven Forums.
No. It would not be safe to turn off all of the features. You would only want to turn off the ones that you do not use. If you are not sure, then it's best to leave them at default to avoid turning a feature off that you may not know that you needed.
You will not gain any hard drive space by turning off a feature, but you may gain a very slight increase in performance by not having features, that may run in the background as a process, that you do not use.
Hope this helps,