Hi and welcome to the beyond blue forums.
These are just my thoughts that I will put out there. Some will be bad or dumb and others not so?
- At some point we have to let our brothers and sisters work it out for themselves. Of course this requires a fair amount of trust. #1
- Without in knowing much about your brother, make sure the goals are achievable. No point in setting he has no chance of reaching. #2
- What sort of boundaries were you thinking of?
- If support is needed ... What options exist in the place going to?
- How much of this will your brother accept?
For me, you come across as a very caring and concerned person which are very good qualities to have. And don't change on my account either. If I were to give any advice... It would be to work out the goals together so you are both part of the plan and he gets to have some ownership and wanting to make it work.
Hope this helps.