I'm not being disrespectful to HK when I respond to this in any way whatsoever, but I, personally, do things almost the exact opposite!
I think the bottom line is: to each their own. What may work for HK doesn't work for me and what works for me might not work for anyone else on the planet.
1 & 2. You'll definitely want to do the text adventure route when you fire up a new game. I'm in your camp with this one. I really only like a VERY small percentage of gamebooks I've run in to and those are likeable because they are UNIQUE and well written of course (see my reviews). Accounting for a wide variety of verbs can be done through adding verbs and custom built commands but it is certainly tedious - I learned this the hard way with "Xanadu 2". It never fails that I think I have thought of nearly everything and a beta-tester would bring it to my attention that their input should work but it didn't. But, in the end, it is very much worth the tediousness to do this. I have a hard time finishing a game when I keep running into the "guess-the-right-verb" to get something obvious done. Personally, I would encourage you to try and limit this happening in your games.
3. Jay just helped me loop a day in my game. After I understood his advice, I looked back and thought... "What was I thinking? That wasn't that hard." So, if you need help with that, ask on the 'Quest Forum' (or PM me) and I would be glad to help you set something up.
Here is where my approach to making games takes a wild turn... I know how I want to start and I know where I want to end - that's it. Then... I just write. As I am writing the game, I learn how to most effectively use the Quest Program (or at least through my first two games). If I tried to learn all the nuances of Quest beforehand (especially coding), I would never even get started. Too overwhelming. I needed to see some progress pronto so I just dove right in. Then I create sub-plots as I go that build up to my main plot, and whenever I need help, I ask on the forums! As far as mapping goes... well, in my first game, I just kind of added rooms as I went. In game two, I had a basic design laid out and created all of my rooms at once and jumped around to work on rooms as sub-plots developed. In game three, I am creating chunks of connected rooms, finishing the chunk, and building another chunk of rooms. I did NOT worry about dialogue until the player ran into an NPC. When they did, I added as many "cases" as possible, then quite often added more as I wanted them to respond to more asks/tells.
If you REALLY want to complete a full game, work on it when you get the bug to do it. If it turns into something you HAVE to do every day, you'll learn to regret it pretty quick. I haven't worked on part 3 of my series in about two weeks, but as soon as I get the bug, I'll go several days in a row and get a big chunk finished. There's no hurry. It's not like a publisher has given you a deadline, right?
Most people probably write/plan the way HK does. I think I am in the minority, but when I have limited way-points, it feels like the story is writing itself. Sometimes I feel like the story is revealing itself to me as I go and almost every time I love how it turns out. If I don't love it, I redesign.
As far as getting things done with Quest, when I started I was DEFINITELY NOT a coder (still am not), but the more I have used it, the more I have understood. If I could travel back in time, I would probably rely on the forums to guide me through a proposed plan I had in mind. I butchered so many sub-plots and now I realize the solution was much easier than the hack job I put together, but I didn't ask for help until I was neck deep in $h!t. That is one of the reasons I tried to put together a basic troubleshooting GUI-editor guide. I hope that maybe you can check it out and see if it is helpful. If it is, awesome! If it isn't, sorry! If you can find areas it needs improvement or additions, please point them out to me. If you need help, ask on the Quest forums as that is where most of my tutorials came from. The name of the tutorial is "Quest - Tutorials and Templates".
Anyway, long story short... My advice is jump right in, ask on the forums if you need help, check out the libraries (if you are comfortable using them), and please consider using my unofficial Quest guide (and feedback is encouraged!).
Good luck! Happy Gaming!
XanMag