Dear Dharmadefender,
I'm not sure that I understand your question. So if my answer does not answer it, then please re-word it for me.
So you say the following: still, at some point, do we not need to experience it as Lord Buddha himself did? Therefore at some point, despite having taken true refuge, won't we will still suffer a rebirth in the three lower realms (no matter how brief)?
I never heard of such requisite, that one needs to go to the lower realms in order to mirror some experience of our kind Master.
Nevertheless, if ever such requisite exists somewhere, you don't have to worry, you can be a 100% sure that you and I and everybody have been in those lower realms an inordinate number of times. Imagine that we are circling in samsara from beginningless time! Since we are still unenlightened, it's a sure bet that we have been unfortunate residents in those unfortunate realms. So it's done.
I would like to tell you a couple of small things about death. It's very important to train our minds in the principal aspects of the path and to maintain a happy mind. It's very important to purposely purify ourselves from past bad deeds ... anything virtuous that we do has the power of purifying us, but of course you have several specific purification practices like Dorje Sempa. After any virtuous activity and at the end of the day, dedicate in order to obtain Buddhahood for the sake of our kind mother beings, and right away, rejoice, always rejoice in your smallest good deed, it makes it very strong and it gives you a happy mind. A happy mind is very important at the time of death because the mind goes to a place compatible with your last thoughts. So now is the time to think about death and be fearful of non virtue, and have regret for the non virtue already accumulated. But at the moment of death one should only remember the good things, and rejoice for them.
No matter what, your kind Guru is going to help you.
These are very general just simple thoughts, there are more things though, wonderful Dharma tools, and I hope to be able to write some more about it for you.