Do you think Q2 (assuming it is R-S-S-R) should be oxidation since it lost H's?
I would say so, yes.
Also, So according the Wikipedia page... so does that mean LiAlH4 only reduces esters and carboxylic acids? Not anything like carboxylate?
Two things, first off - the article I linked to gives the reactions of LiAlH
4 with aldehydes, ketones, esters, azides, carboxylic acids, nitriles, amides and epoxides. It is not limited to carboxylic acids and esters.
Secondly, the first reaction that happens when a carboxylic acid comes into contact with LiAlH
4 is an acid-base reaction that produces the corresponding lithium carboxylate, which is then reduced - so carboxylates will be reduced by LiAlH
4. This reagent will reduce pretty much anything, it is extremely powerful - try to identify the product you would get in each case for Q3.