whether you using a mouse or drum pads the quantize should be either 1/16, 1/32, 1/64 or off completely.
I don't think his issue is quantization. If he's using something like the MPC then he probably won't be looking to play out his whole beat manually. He'd probably look to record a 4 or 8 bar loop and call it a day (in the most part). He's saying that he's struggling to create a notable variation in structure. His hook is sounding the same as his verse.
Unless you're a trained musician (or willing to learn over the next year AND MORE) I'd just stick to sampling. You need an ear to re-create samples which, unless you naturally have it, will take you a while to discover as you train and hone your musical skills (i.e. playing piano). I have two sample-based producers on my label, and a lot of people we have worked with and critiqued us have criticised the lack of variation within our beats. The two of us prefer a straight loop (for the most part) while Elan sometimes likes to layer samples.
However, another producer uses synths and he seems to play his beats (each instrument at a time) for the whole track. This allows him to improvise, or plan a change up for say, the hook. Though, he does try and keep the variation minimal. He has stated in conversations before he wants to keep the Hip Hop blueprint prevalent in his records, despite all of his experimentation in styles and techniques.
If you're making beats and are looking to put them out as just an instrumental (unless as a beat tape to shop to emcees) then you probably will want to create more variation. If you're trying to get an emcee on them eventually, then post-production techniques will allow you to develop more variation throughout the structure of the tracks. A good example is the track Dynamite by the Roots (produced by none other than J Dilla).
As you can tell, the beat is pretty much an 8 bar guitar loop. However, the Roots add variation and definition to the structure by changing the style of ad libs and other techniques. For the intro, there's a vocal. A heavy breathing vocal < for lack of a better name for it. You can also here it in other places throughout the song. On the other hand, the hook possesses two layered takes of the hook, with other effects like delay.
These sorts of things can be added (with the style of the emcee in mind) after you've made the beat, and during and after the recording sessions.
The most important thing for you to do, if you do choose to continue sampling, is to listen and analyse the producers you wish to sound like and emulate their techniques, but change it up. No one wants a twin of a legend. Be you.
Also, to add another aspect to the conversation. The Roots album that Dynamite is off had very little variation throughout the record. Considering, for the most part, the band played for most of the tracks you'd probably expect more variation in a genre like Rock. Naturally, you wouldn't expect as much variation in Hip Hop.