I don't think it matters too much but in general I always prefer dry ferts/additives over liquid in soil because dry tends to be more concentrated and it tends to last longer therefor you get more bang for your buck.
Yes, it does matter. Raw mined humic will have 3 fractions (hopefully) 1 Fulvic, is soluble at all pHs and will be solublized into your tea. 2 Hulmic - alkaline soluble and can precipitate and turn ito a gel in the presence of acid, typically pH 6.0 and below. 3. Humin/Ulmic insoluble and found only in the raw ores.
A soluble powder is prepared with a lot of KOH to achive a higher pH to solublize the humic. Fulvic needs no KOH and is naturally ph 3.0 'ish. If you are wanting all of the benefits witouth the gelling and pH problems go for a fulvic. Second best is a humic liquid. Yes, the extra water is a good thing if you dont want to be adding a alkaline concetrate driving your pH up. Also the liquid will not be a precipitate and have more fulvic.
Raw mined material is best used in mixes and soil type media. As the majority of raw ore is not soluble.
These substances have a hormone like response but also affect your chemistry in a big way because of their cation exchange capacity.