I'm aware that the US has specific requirements around Juice HACCP and I'm not intricately familiar with these, but to me your approach seems like it is going to create a lot of CCPs that potentially don't need to be CCPs.
Certainly there are some risks if a frozen non-aseptic juice product isn't stored or thawed correctly, but IMO it is worth considering whether those risks are significant food safety risks in the context of your hazard analysis, i.e. are they realistically scoring 1/2 in terms of impact, and A/B/C on the probability scale?
I'd start with a bit of a literature review and also look at the nature of your juice raw materials. There are cases of microbiological food poisoning from juices, but in the main a lot of these relate to freshly squeezed products and/or those with higher pHs (e.g. vegetable juices and blends utilising them), particularly in combination with generally poor hygiene practices.
Assuming you are buying fruit juices, most of which will have an intrinsically relatively low pH, and these are also probably pasteurised juices or concentrates where the evaporation stages deliver the equivalent of a 5-log kill, temperature abuse of frozen product is IMEX vastly more likely to lead to spoilage than it is to any pathogenic growth.
I therefore suspect you can build a very reasonable position that most of these stages in your process are not CCPs and are managed by your prerequisite program.
In terms of your temperature limits for thawing processes, it's going to depend to an extent on what it is you are thawing and how. Personally I'd always recommend thawing non-aseptic juices in chilled conditions, so the temp would generally stay below 4C. It can take some time for larger drums to thaw this way, but if you do it in ambient temperatures then you're risking the outer part thawing and starting to ferment, while the inner part is still a block of ice.
It's worth noting that if you're primarily using concentrates then many of these can be used below 0°C - 65/70 Brix products are still liquid well below this, and whilst they are often too viscous to pump or mix at -18°C, you may find they are usable without ever needing to go over 0°C.