It can be a challenge to summon. It is a good idea to be able to throw away anything at any moment, just like the rest of RuneScape Gold and limiting pouches in this way feels unnatural in pvp worlds, let alone what wilderness should look like. It's impossible to come up with an answer, therefore I recommend that you leave the situation in the form of "pouchin invent, combat moves up".
The last thing to mention is that there is no way to have pvp in areas in wilderness. Never. The excitement of the wilderness offered one thing that the pvp/bh realms were lacking, and it was the most efficient management I've ever witnessed.
Pvp meeting pve players. It was possible to utilize the resources available, like treasure trails, runes and dragons to earn rewards. But, it wasn't a mandatory requirement. The above mentioned points for quests are valid because everyone should have access to the content. However, making certain areas safe is not the purpose of the quests. This is the thing I'm most worried about, if there is an uninvolved world that doesn't be attacked, it negates the point of it in the end, and is a source of risk.
There's no reason the runecrafter shouldn't use a dangerous abyss. There are plenty of safe ones just one step away. Zombie-hunters in armour can move to a safer world once they have left the wild. In fact, that could be done for any kind of world. This is a request to don't promote the notion of "safe" worlds or the half-assed wilderness. it is not a good idea and detracts from the fun of being in the wild.
Wilderness, Free Trade
What will happen to the items designed to replace wilderness? A quick background... GE was established about a month prior to the infamous updates meant to replace free trade.
The original design of Old School RuneScape Gold for warriors of the past was to resemble statuettes. But, since the pvp drops back then were not that good, they made the luck drop of ancient warriors equipments so that you could get them and make some money (the economy was very poor at the time).