trust questions

My father was named as 100% beneficiary of his father's trust in the state of Florida. My sister and I were named as subsequent beneficiaries in the case of our father's death. Our questions are:
1) Once estate taxes are paid, what are the pros/cons for my father of keeping the trust intact vs. removing the funds and adding them to his own trust (in which my sister and I are also equal beneficiaries)?
2) If left intact, will estate taxes be due again upon my father's death?
3) If left intact, can my father loan me money from my grandfather's trust and hold my mortgage even though I am a subsequent beneficiary?

Thank you.

To give an intelligent answer a lawyer would have to CAREFULLY review the trust to determine EXACTLY what it says and how it operates, and know a fair bit about the nature of the estate and assets, your father's assets and estate, yours, and everyone's health, etc.

What you want may be wise or not, or doable or not, depending on the circumstances and document.