My big question from reading Leviticus 10:9 is whether all alcohol should be forbidden in the modern church - including communion - or whether this was a highly specific injunction for the Levites, and the principle is more to be very careful in how worship is approached.
I don't, and we (you, I and or others) do not have to assume anything. I, we, should only accept what is written in the bible.
Let's just start with Lev 10.
10:1 And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the Lord, which he commanded them not.
2 And there went out fire from the Lord, and devoured them, and they died before the Lord.
3 Then Moses said unto Aaron, This is it that the Lord spake, saying, I will be sanctified in them that come nigh me, and before all the people I will be glorified. And Aaron held his peace.
4 And Moses called Mishael and Elzaphan, the sons of Uzziel the uncle of Aaron, and said unto them, Come near, carry your brethren from before the sanctuary out of the camp.
5 So they went near, and carried them in their coats out of the camp; as Moses had said.
6 And Moses said unto Aaron, and unto Eleazar and unto Ithamar, his sons, Uncover not your heads, neither rend your clothes; lest ye die, and lest wrath come upon all the people: but let your brethren, the whole house of Israel, bewail the burning which the Lord hath kindled.
7 And ye shall not go out from the door of the tabernacle of the congregation, lest ye die: for the anointing oil of the Lord is upon you. And they did according to the word of Moses.
8 And the Lord spake unto Aaron, saying,
9 Do not drink wine nor strong drink, thou, nor thy sons with thee, when ye go into the tabernacle of the congregation, lest ye die: it shall be a statute for ever throughout your generations:
10 And that ye may put difference between holy and unholy, and between unclean and clean;
11 And that ye may teach the children of Israel all the statutes which the Lord hath spoken unto them by the hand of Moses.
So, looking at the context, would you agree with me that God forbid the drinking of alcohol by those of the Aaronic priesthood and descendancy while they were in service to the Tabernacle/Sanctuary/Temple permanently?