I think you may have some terms and definitions a little bit mixed up.

"Deep Web" - this is just a page or website that can't be indexed by search engines in the traditional sense. The number of these sites gets smaller as search engines become more robust and capable of finding things. But back when searches were just a simple Ctrl-F like feature there were sites and pages that couldn't be indexed by an engine. For example - Plane Ticket Prices, Hotel booking, ect ect. Things that were fluctuating a lot and needed specific time and date type information. You couldn't search "cheapest plane ticket from NYC to SF" and have a result pop up saying $350 or something. Since this information was harder to get at then just "birthplace of King Edward II" it was deeper information or a deepweb. Now a days it can mean a website set not to be indexed by options and things but it is still just an unindexed website.

"Darkweb" "Darknet" - Websites that are not on the standard www protocol. They are most commonly on the onion network protocol (TOR) or http://onion.xxx vs http://www.xxx which helps mask location of the server as well as content coming in and out of the website. The onion protocol is only accessible from a TOR connection. Thus onion websites can only be accessed by TOR enabled browsers. TOR itself acts just like a VPN so it can be enabled on almost any browser, but there are browser packages that are made to simplify this process for the end user.

Now there are some things misleading in your statement that send up lots of red flags for your claimed knowledge, I'll make a list of things that scare me as your comments go on.

"I know how the tor browser functions (P2P architecture)" - Good perfect summation of what needs to be said about that. "I know that the deep web is a majority of the internet" - I am not 100% sure if this is a true statement or not at this point in time, as the deepweb is just pages that you can't google for. But the way you phrase it makes it sound like there is this huge "secret" internet thing, but that whole concept would be ridiculous. How could that be true if the majority of the population wouldn't be able to access it, and the majority of the population makes up the majority of the internet. Websites are there to make profits, if nobody can access your website why make it? This is where you start confusing deep and dark web and I start getting really scared of where you're going with this. " going on the deep web as an average Joe isn't dangerous unless you venture onto a dark website" - at this point I have discovered with 100% certainty that you're confusing ideas and concepts and are either just regurgitating something someone else said or are just trying to sound smart about something you're not 100% clear on. "there is a piece of maleware (like the FBI used previously) " - a lot of TOR browsers limit what scripts can and can't run on a website and automatic downloads and injections would for sure be disabled, and most users of TOR browsers that I know of have more add-ons and things that block all scripts and monitors incoming data. "that could potentially get a read on your location." - why would the FBI care you're using the darknet? unless you're doing something illegal, but most illegal things on the darknet are drugs and that falls under DEA not FBI.

There is my breakdown of your comments for your review.

As to answer your questions, I use TOR browsers occasionally to visit normal websites to help mask my identity and I have used them to connect to onion websites. I don't use them often but if there is an occasion or something that requires it I will use it.