I stumbled upon something which may also be of good use. I could have shown it but due to time and also complexity, best to read it as a article.
The article explains why you do not see the 3-4% in the initial years.
To answer your question on the 3-4%, it is the expected amount (since the inception of endowment policies), that this would not be cut (case in point, AIG did cut 100% Terminal Bonus during the crisis).
It also depends on the policies (the gauranteed column).
No. It is not guaranteed. The 3-4% pa is merely to entice you to buy the policy. Only the reversionary bonuses declared every year is guaranteed. Do note the reversionary bonuses declared is less than 3-4% because of insurance companies' practice of smoothing the bonuses. That being said, I am not saying insurance is not important. Insurance is in fact very important. But you need to buy the right type of insurance. Just my humble opinion.
No, but due to smoothing of bonuses and Reversionary bonuses being guaranteed once declared yearly, plus the fact that when insurers cut bonuses it would usually affect Terminal bonuses or the policies maturing during that year, that 3-4% is expected.