If the list of IP addresses only list addresses that you use, you have nothing to be worried about, in terms of the potential of another user accessing your account. You should not have these issues, providing you verify each computer to your account.
It appears that you might run into other complications if you are simply using a dynamic IP, and the computer itself does not change. Past that, it is best that you contact Steam support, to determine the best course of action in preventing this sort of thing happening again.
At the end of the day, it does not appear to be anything to worry about in the long run. You have not appeared to be flagged for illegal activity, or anything else that might get your account banned. However, while account limitations like this can be easy to lift, you might worry that should the same problem arise again later, you would have the same inconvenience of lifting it before you can use the features that have been restricted.