I run Cubase in Windows, both on a PC in the control room and on a laptop at a keyboard workstation. No matter which DAW you go with, you'll need an audio interface, which can be as cheap as a few hundred bucks, or more if you want more inputs. Pro Tools has the "industry standard" image but that's not really relevant these days like it used to be unless you're doing pro work and need to interface with audio or post facilities. There's also Reaper, FL Studio, Cakewalk, Studio One, Logic (Mac only) and I'm probably forgetting a few. None are perfect, all have their benefits. Cubase is just what works for me.
Honestly, most DAWs do pretty much the same basic things, especially for old school tracking and mixing (I'm a classic rock / blues guy myself). As to whether or not it's worth throwing money into, the real question is do you want to do recording or not? If you do, definitely worth it and the Kemper is awesome in a recording context, both tone and workflow.
There are lots of things you can tweak on the Kemper including EQ, compression, gain, stomp boxes, etc. and a lot of guys here tweak most of their profiles to taste. There's a lot of flexibility and room to play with a profile, and the new Rig Manager has an editor to make it easy to do from your PC (Windows 10 only).
There's an alternate workflow others use (and I fall into this camp) of just having a good collection of profiles appropriate to their taste and simply using them right out of the box. If profile A doesn't do it for me, I just move on to profile B. Rig Manager lets you sort by gain among other things, which makes that kind of browsing easy. If you get good profiles, whether free from Rig Exchange or from commercial profilers, you can certainly use them as is.
Which path you prefer is more about personal preference than "better." I hate tweaking and I've never been very good at dialing in tones even on tube amps, so for me using ready to go profiles from people who are good at dialing in tones is perfect. For others, the tone hunt and the tweaking is part of the fun, and as you noted there's plenty to play with.
Either way, it's first class fun, man.