The Fairphone 1 and Fairphone 1U are not open hardware. They are modified versions of a pre-existing, proprietary asian phone. The Software is partially open source, other parts are proprietary e.g. to mediatek, the chipset manufacturer.
For the next Fairphone we don’t know theese things yet.
The open source parts are available. I believe this is where.
If you encounter any problems you should post them in the right category/topic on the forum. Problems that many users experience will be moved to the bugs category where the moderators will invite Fairphone Officials to join in the discussion. (Since they are buisy they can’t check all topics on this community run forum).
If you want to be able to find more bugs you can join the beta testing program, but I guess there is currently no sense in joining because the latest beta version is very close to being rolled out to the public anyway.
Unfortunately with the current Fairphone Android upgrades beyond 4.2.2 are very unlikely.