OK so, The Witcher 1 and2 - should I play them?

I recommend playing them. Witcher 1 was developed on BioWare's aurora engine, and it looks it, primary with character models, but the rest of the game looks fine. Gameplay wise Witcher 1 is more of a rhythm game than anything, where you have to properly time mouse clicks for best results, its not the most engaging, but I don't mind it. I just play on easy, and I don't bother with alchemy at all. Magic is pretty basic in these games, you are probably just going to alternate between your wind and fire skills most of the time. Witcher 1's biggest detractor is probably poor map design with a lot a back and forth quest design, but if you stick with it, it is a really enjoyable game in my opinion, I quite enjoyed the story and setting, more than a few people hold it in higher regard than the Witcher 2.

To be honest, I don't recall there being too many QTE's in TW2, when I think gameplay annoyance, I think of the Kayran boss fight that has a seemingly intentional obtuse and counter intuitive solution. Again I play Witcher 2 on easy and don't bother with alchemy. Witcher 2 is a hack and slash, with broken hit boxes that would probably drive someone insane on higher difficulty, but on easy I don't have any trouble. None of these games are overly stat based, they're fairly simplistic, Witcher trilogy and Mass Effect trilogy have a lot in common in many ways. Story wise Witcher 2 is in the Obsidian mold where it reaches so high, but execution isn't quite there. Haha. Personally I'm willing to look past some plot holes/contrivances because if you can what's here is really good, and feels right at home within Sapkowski's Witcher.

Interesting, and thank you. I've never played a 'rhythm game' in my entire life, but to the best of my knowledge you have to follow a beat when it comes to combat, timing your attacks to the drum groove or whatever - I'm thinking that TW1 isn't actually like that and you had something else in mind when you made the comparison.

As for difficulty I almost always start games I'm a complete newbie at on easy- at least initially, and if I find that there's no challenge at all I'll up the difficulty accordingly.

One final question then: Is it a good idea to read The Witcher novels before beginning to get a better idea of the world and back story?

I own TW1 - because it was free on GoG - but haven’t played it.

I liked TW2 well enough. I think I have about 90 hours in it for two completed runs. I don’t really care for the combat and I really don’t care for the inventory system, but is an impressive game given when it released.

TW3 is one of the all time greats, in my opinion. The combat is recognisable from the 2nd game, but with enough evolution to be fun and accessible, rather than a pain in the ass. Geralt is much easier to like - if that matters to you - than in 2, and with Blood and Wine, they have one of the best, maybe even the best send off for a fictional character that I can remember. Certainly the best in my experience with games.

Regarding TW1, yes, the graphics aren't great by today's standards, and the story is probably the weakest of the trilogy, but it's still a pretty decent game, and I didn't feel like I had to spend a ton of time working on stats and items (and I *do* bother with alchemy). As for back-and-forth quests, I can think of other games that wasted a lot more of my time on boring sidequests than TW1 did, including a couple from Bioware (DAI and MEA). The one other thing that feels kind of "off" is that when an NPC runs out of things to say, they may cycle back and repeat an earlier line, as opposed to games where dialogue flows a little more naturally. One character in particular will warn you that "THE WATER LORDS ARE NIGH" over and over if you exhaust all her dialogue choices.

TW2 is an improvement in gameplay and concept, though it may leave you confused if you don't know the Witcherverse's backstory. (I certainly didn't know what the hell was going on by the end of my first playthrough.) I'd advise either paying close attention to the codex entries or look for a lore guide that doesn't spoil too much of the game. And the immediate context is usually clear enough to let you understand the implications of whatever choices you make as Geralt.

TW3 deserves all the accolades it's received. The one thing I'd warn new players about is that you might end up choosing the romance with either Yennefer or Triss before you even cross paths with the other, and I'm not sure there's a way to change your mind later.

Only you can answer. I did only play TW3. TW1 I stopped during prologue when I found no chest to dump inventory and after enemies spawned way behind and killed the escort target.
TW2 I had twice trouble with QT events, once I repeated a dozen times until I looked up how to do it. I stopped at the endfight for 1st act at bossfight in a tiny room I just couldnt win.

OK I'm convinced, and in fact I've bought the complete series of Witcher novels. I'm going to be starting on the first one probably around next month, as I have other books to complete first.

After that I'll fire up TW:1 and see how I go.