I think yes. Most digital artists I watch and learn from use Wacom products, so I would highly recommend getting a tablet or something similar if you can.
Yeah, tablets are HIGHLY recommended. They make your life tons easier and because they mimic the feeling of traditional art, the experience feels more authentic and you'll achieve better quality in your pieces. With a mouse, it's highly unlikely you'll get the result you want. My digital pieces improved dramatically after switching over to a tablet.
If you are starting, I recommend a basic Wacom tablet, like the bamboo series, for example, it's going to be cheaper, practice a lot, then get a better one. :)
You don't need a tablet to make great digital art but it really helps and makes everything faster, easier and simpler. I've had a lot of great tablets that weren't from Wacom and I recommend shopping around and reading reviews if you're going to purchase one.
No. There are artists who get by and do amazing work with just a mouse.
Tablets can help you be more efficient and there are other(cheaper)brands besides Wacom such as
Huion, Yiynova, Monoprice, Turcom, Ugee, Tooya, etc.
If you want to be a digital artist then yes, you almost certainly need a graphic tablet. If you are more traditional artist, then you need pencil and paper
Any graphic tablet would do, even Genius has some very cheap ones (30$). But if you intend to buy a graphic tablet with a screen, then go with Wacom. Monoprice doesnt sell spare pens which means you can throw the whole product away if you lose your pen... And after researching the whole internet about graphic tablets, I found out that other products can do good as well, for example Huion tablets, but lacks support for their customers. Wacom isn`t the industry standard for nothing. Actually all alternatives to wacom are "chinese" replicas, or so they seem, so don`t expect quality materials from Monoprice/Huion/... So in the end, why buy a low end graphic tablet if you will need to buy a new one in a year... Buy a Wacom, and I recommend one of the better models (if you are serious about drawing), because investing in a lower priced wacom will definately lead to you wanting to buy a better one. Might as well save for the better ones (cinteq) from the beginning rather then first buying a cheap wacom(intuos) and than later a cinteq. My two cents about tablets ;) Hope it will help someone