Great questions
I can answer based on our own strategy for FIRE, but it may not apply to your situation.
1. Currently, we aim for 3.8, but we will adapt until we reach retirement. 3.5% is likely fine. Our worst enemy as Swiss investors is the depreciation of USD.
2. We plan to go 100% stocks. But if you plan to be more conservative, a great strategy is an equity glidepath. You start with 20% bonds (or cash) for instance and you slowly sell them to go 100% stocks. This way, bonds, and stocks are doing what they are great for, respectively short and long term.
5. We plan to keep a house in retirement. Our plan for that is to have a long-term mortgage before we retire to avoid issues renewing it and prepare significant enough margin so that banks won't be deterred.
