I think bows are fantastic. With mastery, and ranks like 15, you can do tons of damage, maybe faster than with anything else except blasters or the big outdoor area-effect spells. In MM6, you don't even need to be an archer to get this, which is as bad as it is good because for this reason I don't play archer--they don't get any special use of bows, which would sort of be the point.
Beating the Temple of Baa at level 8 was quite an achievement. There are just tons of monsters. Since you finished it, there is no point giving any advice about it, but what you want are indoor area-effect spells, especially Fireball, Inferno, and Ring of Fire. I normally don't go there until much higher level. When I first played through it, Ring of Fire just saved my party when I was surrounded once or twice, and it helps to have plenty of blue potions which give you more spell points. I luckily had this, and I think I was about 8th level, but it was a very long time ago (I bought and played it when it first came out).