The context of that is entirely different than a "do we need QA" context. "Think and Analyze" is an abstract philosophy, not a process for engineering.
I'd say that if you have a T&A team it would be great to measure and publish your defect rate. Of course, if you just have better than average coders, then naturally your defect rate can be low.
But even a low defect rate does not preclude having a formal QA process. Even the best coders in the world can ship the wrong product when the specifications are wrong.
I used to run a QA department for a large e-commerce company and love what this article has to say. Nothing gets executive attention like putting a dollar value on downtime (like $1k per minute on a slow day).
A sysadmin knows and loves the OS. Can script to craft utilities for repetitive tasks. Can field strip and installation down to device drives. Can provision identical systems in his/her sleep. Can solve critical problems under pressure. Is not afraid of doing it live. Will argue for a test lab endlessly. Has read the Bash man page. Favors practicality over aesthetics. Uses the right tool.
If you are starting a technical company you will need more than a passing familiarity with technology. To be successful as a software company you will need to assess the quality of the code you receive as well as need to know enough to manage a software development project.
To think that you can contract a coder and get a company back is fairly naive.
Also, plan on a long term relationship. "Rent" sounds like you'll toss the sysadmin away and when new work pops up you'll just fetch another one. Don't do that. Establish a relationship as you may grow into needing a lot of work done.
I don't think you want to "rent a sysadmin" (that sounds real low brow to me). Instead look for a contact sysadmin but first make a list of the tasks you want to hand off. If it's a logical grouping you may find that a managed host can take care of you (like SliceHost or DreamHost). If not, then use that as a job posting a la 'Seeking Linux Contractor' and screen carefully. Your best candidate will likely have a couple long term clients they take care of a little room for a new one.
"that challenging kids and allowing them to excel is considered child abuse."
Actually that's nothing like my sentiment. There is an age and time appropriateness that shouldn't be overlooked. Immersive study is excellent - my own daughter had my support to immerse into Argentina for 6 months when she was only 17 and I certainly wouldn't have considered it unless she had life skills, coping skills and emotional maturity.
But, plunking a kindergartener into an immersive foreign language and culture environment is dubious wisdom.
While parenting is most certainly not deterministic, it does seem to me that the child (especially the youngest) experienced quite a bit of unnecessary suffering so that the author could proceed with an experiment. That the suffering ended with fairly positive results is as serendipitous as any non-deterministic process.