If you has the appropriate gears and charms, it will be easy for you to get 2 stats to 90+. So nothing much to worry on it. And in order to collect your charms earlier, try reach aleroth as early as possible.
And it will still too early for you to decide how much on each stats for now, unless you get the end game gears. But I think you should roughly know how to manage that already.
As for bow magic damage, you will eventually had magic damage on it or even now, as I do believe you should have bow with 2 enchantment slots. For weapon enchantment slots, I will always put in damage enchantment, so 1 slot will go to normal damage and another slot will be magical damage. There where int will increase your bow base damage.
