For unbalanced runs, absolutely keep them under 10meters and the shorter the better due to noise issues.
Hosa is ok enough if you're hooking them up once in a low duty home studio and practically not touching them and never expect to sell them, but if they'll ever leave the house or you intend to use them commercially or want them to have any resale value at all, get something better. Head over to Redco and price yourself out a custom RCA to TS snake, it doesn't have to be super pricey depending on the cable stock and connectors you pick.
For your purposes, fancy cable stock isn't really important, but it is always worth getting better quality connectors! Nickel connectors need periodic cleaning, gold connectors stay cleaner and are more conductive. Hosa have as lousy quality connectors as I've seen.