Bow will hit less since DEX isn't your main attack stat, STR is. If you are primary bow user, then DEX should be your focus, put the 18 there and then just use finesse weapons so you can use DEX as your main stat. If allowed to adjust (consult DM) flip the 18 into DEX, DEX fighters are perfectly viable now.
You can also be mostly melee with just dex weapons, the rapier is d8 just like a longsword. The Hit and Run angle can be covered with the two-weapon fighting if that's your style, that takes up your bonus action but you can get another attack in with full modifiers. Legolas fought with 2 daggers, or shortswords if you are being generous.
The bow is magical, so it should be your primary weapon. It uses DEX, so get that up if your DM doesn't allow you to switch.
Look at Pushing Attack, Trip attack and Distracting attack. Elusive is redundant with Mobile, and only applies to OppAtt. Pushing attack and trip attack can keep them away from you so you can shoot them more, and distracting attack works well if you are shooting into melee as your heavy hitters can then attack with advantage.