I made a first attempt to install BIAB 2017 at the beginning of the year but didn't get much further after that due to time constraints.

I should have more time in the next little while.

Some basic questions...

1. What is the absolute minimum drive space required to install the BIAB core. Again only the absolute core of the program, no styles, user styles, .wav files, add-ons, etc. etc.

2. Can the program itself be run from a USB drive?

3. Has the installation part of the program changed since January to now allow the user to choose exactly which parts of the program they wish to install and which to leave for later?

4. Can the program be installed on several devices? Desktop, notebook, tablet etc.?

TIA

1:
Not sure what the minimum drive space is but it is very small if you:

2: choose the Minimum Install option, and run from USB drive.

System Requirements are here

3: Not sure, someone else will be able to advise more clearly

4: Yes, generally speaking. PG Music may allow you to register the program on more than one device owned and used by you.

To add a bit:

You have three activations (and you can deactivate and change a device).

By 'tablet', only some will work (not an iPad, for example). It is my understanding a Surface does run BIAB.

I don't recall any changed install options in many years, just the same four.

1. What is the absolute minimum drive space required to install the BIAB core. Again only the absolute core of the program, no styles, user styles, .wav files, add-ons, etc. etc.

Can't say exactly how much space is required, but minimally, this goes along with question #2. You'll need to select the option to run from the USB drive, but that will install the required fonts, the DX effects, the Coyote WT wrapper DXi, Sforzando (if you want to use the super midi tracks), and a few other things, but not a lot, and then, question #2.

2. Can the program itself be run from a USB drive?

Absolutely you can run both BIAB and RealBand from the USB drive.

3. Has the installation part of the program changed since January to now allow the user to choose exactly which parts of the program they wish to install and which to leave for later?

I think the only major change is the switch from using Sampletank for Super MIDI Tracks to using Sforzando instead. I think everything else pretty much is the same as it has always been.

4. Can the program be installed on several devices? Desktop, notebook, tablet etc.?

You can definitely run on multiple devices up to three registered activations. You can deactivate and reactivate if you need to use another computer. This works fine for desktops and laptops. I understand the MS Surface works, but only the one that runs Windows 10 desktop apps.

I notice a tablet seems to be a bit of a hangup here in the responses. Likely this is because of Windows OS requirement.

In my experience, if a tablet can run Windows, it'll run BiaB/RB.
A Surface would work, and I've seen it run fine on an ASUS (windows) tablet also (using external drive for generation, etc).
An iPad would probably be a much bigger challenge since Windows OS is not native.

Just mentioning; an iPad would be fine to play the 'result' (mp3 or whatever) but for running the actual app it would be more challenging to actually Run the BiaB app.

/I don't have the Mac version of BiaB to test, but just having the Windows version I would expect issues with some non-Windows tablets. My W8 tablet seems to run it OK here.
//Not sure if having the Mac version even makes a difference, since I don't have it

Using the minimum install configuration is also the fastest install since only the operational part of the programs need to be installed on the main computer.

This is how I have run BB now for many years.

Excellent. This will be really helpful because I may wish to deactivate on some notebook/tablet and switch to another.
It's good they have this flexibility.

Thanks the rest of you guys for your replies! Also helpful.