Thanks Dave, one great thing on this forum is it stays far more civil than most any other I visit. The various Subaru enthusiast forums are good for a lot of info but often you have to wade knee deep in battles to find the low lying gem here and there.
With that said I'm going to take a crack at responding to (not necessarily answering) our new build partner's questions.
To Prematureapex,
I'll have to generalize and offer opinion, since I'm not even on the road yet myself. So yah, take me with a grain of salt if you like.
I feel like you asked the wrong group of people regarding your specific points. I'll trickle that out in the next paragraphs.
For the most part I feel that the members interested in posting here tend to be more involved in their builds than just following the book. Conversely builders who are staying within the plan ...by the book for all practical purposes... don't seem to be the ones who have a lot to post. So your audience consists of builders who are not likely shooting for the minimum acceptible design/build per FFR's plans. In other words, the silent majority probably could address your thoughts about the build creep vs "stock" and track abilities, but they are not in attendance here. Not only that, taken as a whole, the active posting members are a pretty small club, even though there have been a lot of posters since incept. So it's not like you have auditorium of diverse builder/people to draw from
I personally think the car can be built safely and at the 15-20K price range, I'm not much over that $20K myself, but my style is still modify like crazy, but for some things, I make instead of buying. (My tool purchases are another story). Why I believe it can be done... and I'm just shooting from the hip here:
I believe the car's design is decent if not better than that, with FFR's background and engineering efforts in it. Some dispute this and have their own good reasons, and when they've shared thoughts I don't dispute them.... But let's say now what if you stick with FFR's supplied parts, plan. Obtain a donor with decent components, and if you take time you can get one (and maybe you have to have good luck, but they do come and go, I know, I watched the donor scene for 2 years before starting in). My opinion is that Subaru builds a good product with acceptable materials. If you use your donor parts throughout, and they are in reasonable mechanical condition it seems to me the 818 will come out at price point, be reliable component wise and capable of being thrashed now and then just like it's donor may have been. You're even allowed to buy a few new parts that broke during teardown, but don't get fancy or upgrade happy. With common sense you could track it once in a while, for fun, maybe not to win all out against all comers. Track activity expenses are ALWAYS extra, i.e. you break it you fix it and that is not on FFR's plate, costs wise.
With a few and I hope I'm not insulting by saying this, after all, reading the threads (I've probably read all and several more than once) I see people showing, asking, thinking and generally building improvements, changes, adjustments and so on. Because? ...faster ...safer ...fancier ...personal and so on. I.e. the group you're talking to is THAT group, again NOT the base build group.
So one more time why are you asking the wrong group then, well I think the group are almost all in sync with doing differently than the FFR manual and supplied parts, for the above and more reasons. They just don't have the perspective of building the car at FFR's published base cost. The interest may have been there at first but then improvement and customization changes our plans.
What about the deficiencies, problems, body fit compaints, etc. and costs/time/work to solve those? Do they count in the equation? I think yes and no, how you tackle them and in many cases are we dealing with opinions, real problems, not safe and so on. There has been so much covered in this whole area that no one post, or even one thread can address the topic in one stab. I do think that given the time needed to build one of these, anyone serious about building a good 818, safe, cost controlled, customized or not and so forth, does themselves great favor in reading the threads.
Again I think you can build it by the book with minimum time and cost, which I'd bet is under or up to $20K, oh and it'll be fun to drive and go fast. (Unless you are a self painter, you'll have to for-go that $8K paint job). If that is your goal then you know what to do from here and I'd wonder if you'd ever even need to post another question. You won't find a lot of posters here going that route though, so don't be surprised that they haven't given you the magic bullet you're looking for.
If you want the detailed explanations about all this, you've got a LOT of 818 forum reading to do, everything you're wondering about IS in here - really!!!
One other thought, the builders who could really give you authoritative comment in many cases may well have moved on with their lives. Building something else and no time for this particular forum.