I'm not sure I understand why people are saying this is necessary.
As many people know, I personally use a longbow along with a one slot melee weapon (langes messer), I have never had a problem with this and although I am classed to be a melee/archer hybrid it doesn't make much of a difference that I carry only one stack of arrows.
At level 30 I was using the following build;
Strength: 18
Agility: 21
Athletics: 7
Power Strike: 3
Power Draw: 6
Weapon Master: 7
Archery: 159
Two Handed: 55
Now, even if you don't have the powerstrike or the melee wpf, it is still perfectly viable to carry a decent melee weapon with you. Sure you've got a slightly limited arsenal, particularly if you want to use polearms or two handers, but at the end of the day, you can do it.
Archers have been nerfed and buggered continually but at the end of the day, they're still usable, ok, you can't run but I look around on the battlefield and I still see that the most noticable archers are the ones who are a good shot but are able to defend themselves in melee. You don't need the wpf for melee although it helps but sacrificing a few points (I believe 6 or so) in archery for the ability to swing significantly faster is well worth it.
I completely disagree with your suggestions as although you can't kite as well as you used to, you already have the ability to defend yourselves with a few very little negatives.
There is no need to reduce the slot requirement on the higher powered bows, if you choose to use those then you have several options. There is a 0 slot hammer that allows you to block, although it's quite crap in attacking back, you still have something, you take that and an extra stack of arrows for your War bow/Longbow then it's your choice, or you do as I do, drop one stack of arrows in favour of a proper melee weapon. If you don't like that, then you can take two stacks of arrows but class with the fact that you'll need to grab a melee weapon at some point and hunt the battlefield.
Alternatively you can use a one slot bow and take a proper melee weapon and two stacks of arrows, or go one further, take a 2 slot melee weapon, such as the Heavy Bastard Sword (Quicker weapons for obvious reasons) and one stack of arrows.
The options are there, there is just no need to lower the slots or increase the number of arrows in a stack, both of those might be useful if there was a problem, but there isn't. I've played as an archer since day one (Ignore the HA phase, I still had a bow) and throughout that time I have always carried a melee weapon, and always a decent one.
17 arrows is more than enough for me, and there are always plenty of them scattered around the battlefield if you ever need a quick restock. I'm not here to shout "adapt" or any of that crap at you, I'm here to say that it's not a change that's needed and to offer a couple of already apparent solutions.
At the end of the day, you increase the number of arrows, you run the risk of archers suddenly having 50 masterwork bodkin arrows to shoot, increasing the incentive to run or you allow them to have a decent melee weapon, 34 masterwork bodkin arrows and more archers with the more powerful bows.
Even if you're not good in melee as an archer, use your head, there are plenty of ways to get one over on your melee counterparts.
In short, increase the number of arrows = more arrows for someone to shoot at you as they back away.
lower the slots on the two high powered bows = more archers dealing more damage with the same number of arrows & decent melee.
I hope this makes sense, I wrote it quite hastily and although I have proof read it several times, I've never been fantastic at not rambling!