FieldType Comments Up/Down votes and Reply button question

[MilenKo 89]

Good day fellas. I was working on a theme that required me to setup a comment system with star rating and votes and it is all completed markup wise, however I noticed something strange during the test - if the field option is set to use Up/Down votes a user can do both simultaneously. My question is, would it be possible to allow ONLY up or down-vote to be used at a single time as presently I could click that I like a page and at the same time dislike it. Logically, if I would click to like the page and then click to dislike it, it would diminish my previous vote and only allow to either like or not a page.

Also, when in the field settings I set a reply depth, I would like to have the Reply button still showing instead of disappearing. It is much more functional to have the reply button showing even after the depth limit is reached which would allow the user to reply quickly if a lot of comments are shown on the page. Instead of scrolling down to the comment adding form, the reply button would still show it under the chosen comment, however the indent would stop changing.

Any ideas how to allow only one voting at the time and keep the reply button after the depth limit is reached would be really appreciated. I am attaching an image to better demonstrate the need...