How do I view the content of the particular version ?
To view version history for your list or library for a specific item.
- Click on
...
then ...
then version History as shown below.

- or select your doc and from the above ribbon select Version history as shown below.

- the following version history dialog will appear to you to see all previous version

- click on your required version to view only without restore it, or if you need to can restore it or delete it as you like.
Do I have to restore it to view it ?
No, only click on the version that you need to view ,you also have three option view / restore / delete.

Can compare the content of a specific version?
No, you can compare modified by and modified date and size but content compare are achieved manually.
but also there's a workaround to compare office doc from word itself as the following

For more details about content compare with word check this
[Update]
Please try using Internet Explorer and also inPrivate mode (CTRL + SHIFT + P) to
- open the file and see if the issue persists.
- The difference between the Right-click > Save link as and the Left-click is - only that a left click will directly open the associated Office application. Office should detect and automatically opens the file as long as the file type is associated with the application. The link never opens in Office Online.
Check the ref