No. 出し is a 連用形, which means it never modifies a noun as a relative clause. 連用形 literally roughly means "continue-verb-form". That 出し modifies nothing. Just because a verb comes before a noun doesn't mean it's a relative clause.
Compare the following two sentences.
I ran across the ground and called my teacher.
Yes, 酒を飲ませる人 is ambiguous. In general, this ambiguity can happen in Japanese relative clauses typically when a verb takes two or more human arguments (～が, ～に, ～を, etc). Here are similar questions:
Clarification about how 惚れた should be translated
が in subordinate clauses
How does the passive form work here?
The meaning of ”あれは魔術師に与えられた祝福”
Relative Clause ...
Firstly, using the particle が would make no sense at all. が marks the subject of a verb, so 先週がセーターを買いました would mean that "last week bought a jumper". Unless you have some bizarre world where you have anthropomorphised the weeks then this sentence is pure gibberish.
は and が are not interchangeable (see this). は can mark a subject, but it does not ...
Before talking about relative clauses, you have to fix several basic errors.
Why did you suddenly choose 貨幣 instead of お金? 貨幣 is an uncommon academic term that mainly refers to physical objects to use as cash (e.g., banknotes and coins). It's not a suitable word when you talk about the importance of money in daily life.
The use of 値打ち is wrong, too. First, ...