Dublin ,AAM would need a lot more info to give you solid answers but a few things.
1. Can you afford to repay @ 2.35% over 35 years V caught with 18 years on tracker.
2.You owe k400 , is property now worth k400+.
3. Rates on tracker or variable are felt must go up in the next few years.I do not see the Bank increasing variable by any more than the increase in trackers (you may have to trust them on this?)
4. Good independent advice, is very hard to get.The reason Banks now routinely put in that clause is to protect them ,and to warn you before you sign.
5. I would always ensure the family home gets 1st priority.
(in particular if investment is in your sole name)
6. You are not really signing away k150, if this offer works you are protecting investment and family home.
The k150 is only a future guess, who knows how the next 5 years will work out?
Ultimately , it is your decision, so good luck.