You describe many technical solutions so I think you have that bit covered. The next step would be to consider some broader questions like
- What is quality?
- To whom is this quality?
- Is it important to them?
- Why is it important to them?
- Do they really want to pay for it? Less or more than they are now?
- Would they rather pay for something else?
- Do we collect statistical evidence of quality, as defined by the customer?
- Are we able to continually reduce costs and prices due to quality improvements?
- Are we chasing ghosts sometimes? Or do we only take action on real problems?
- What are threats to our current level of quality?
- How do we Institute a culture that ensures quality 3 years from now? 5? 10?
- is our level of quality constrained to the code, or do we have high quality relations with the customer too? How do we know? What is the biggest point of improvement in customer relations?
- Is our documentation high quality? Installation instructions, user guides?
- Do we have high quality in our relationships with our suppliers? How do we know? What's the biggest point of improvement?
There's a huge amount of literature on quality control. Much of it is from the 1960's or before, but it's just as important today. Deming's 14 points and deadly diseases are a good start, but I'd recommend continuing with his book Out of the Crisis, following whatever references you like (Shewhart, Juran, Taiichi Ohno, Reinertsen, Wheeler, a little depending on where you want to start.)