The only jobs that would likely exist after a heavy 'cleansing' of fluff jobs are those that it really makes more sense for people to do over machines. I believe this is inevitable so why shouldn't we plan accordingly.
IMHO, the ONLY problem with that is the level of pay seems (from today's standpoint) to be too low to sustain the population. e.g. keep pay the same and cut 85% of the jobs would equal 15% of the cumulative income. This is the problem I think we should discuss how to work out (below).
The issue of 'can every family derive an income in a supposed robot-technician-only world' is a different one. I don't see this as a problem because if the wealth issue was solved, I believe people would have more than enough wealth and we would go back to paying artists, composers, writers and other creative types (digital yet to come?) much more readily. Also, look how simplified PC troubleshooting has become in the last decade. We used to have to intimately know how all the inner hardware worked to fix programs and incompatibilities. Now, we only have to know spam and reloading software.
The wealth issue, for me, is easily solved by the elimination of the theft shown in my 'Old Math' post at http://www.dailypaul.com/274581/old-math where I lay out how 60+% of our income is stolen from us. With that returned, we could retire by age 30, literally. The reason that is so profound is because of the following.
If your discretionary or 'extra' money each month amounted to $300 and you get a $300/month raise, you have effectively doubled your perceived wealth. If you instead received a 300% or 400% raise (by keeping the wealth robbed from you now), your perceived wealth is anywhere from 5-15 times what it used to be. That's up to a 1500% increase!
With those raises possible in a very real way, retirement ages will plummet to around age 30. By retiring in 8 years instead of 40, you will be passing your job on to 4 other people during what would have been your original career length. This is effectively employing 5 times the people, so instead of 15% 'employment', we would be looking at 75% 'employment'. So far, ALL OF THIS IS ABSOLUTELY POSSIBLE TODAY.
So the only one of your issues left is how to employ those not smart enough for robotics and not creative enough for the arts. I highly doubt that there won't be enough jobs left for the small number of people that affects. Surely, there is at least one breadwinner in each family smart enough to do social work, counselling, or sponge baths for the disabled. If not, well maybe our education system will morph into something a little more educational.
By the way, on growing food in an apartment... Next year, you'll see a turnkey home aquaponics system that fits in a 6 foot cube, indoors and supplies four people with all their veggies, fish and shrimp year round, plus barter stock.