If you have fat and clumsy fingers like me, you'r jsut a typo away from getting stuck in BFE. I've thought about this a bit and I've come to a reasonable trade off.
First of all there is the issue of newbie recruitment. It brings us back that old system of lo/li. moreover, lo/li is exploitable to cheapen the TW cost of traveling. Although it's truly more efficient to travel with carried items, namely a 2 chest boat or what have you. I should think it reasonable, that if one has 0 TW, they should be able to travel ANY distance at the expense of a full TW and no more (e.g. the consequences of travel over TW suggested below). This would allow newbies to be recruited to villages very far away. It would also make it FEASABLE for anyone, at any distance to trade using the in game machanix as designed (versus lo/li). It would just be significantly more expensive for newbies who would also suffer the far reaches of intoxication for frequent trading.
One should not have to lo/li to travel to hearth. This should be an in game function. In fact regarless of TW one should be able to travel just about anywhere. If your desired destination would overspend your TW, you should suffer SHP damage @ 3:1 for each % of TW over your cap. If you have less than 2 SHP you should suffer HHP @ 2:1. Maybe play with those numbers a bit. But it would mean one has recourse after spending TW from a typo or miscalculation and not being stuck at an unreasonable walkign distance from any desirable locations (stuck @ RoB, huntign hearth, resource gathering etc. BFE) while making the toll exacting enough not to be abused.
Downside, you could die. Solution, Make a check or just prevent suicidal teleporting altogether. This system couldn't be more forgiving and you should always be able to log in at hearth without incuring physical damage so that one isn't teleported to hearth because of a bug and stuck with 2 HHP in LX territory. An unlikely scenario, and possibly abusable but as before it's much more efficient to just maintain TW with alcohol and use carried items. The siginidficant intoxication incured from reducing one's TW to %0. This makes it feasable, granted expensive, for newbies to conduct trade. the making of alcohol is certainly within the reach of any newbie capable of setting up a settlement far out enough to require such quanitities. IT adds to the sandbox effect and and makes more things possible with a fair cost of doing such things.
Tl;dr? MWoT Skip:
Travel from %0 TW should cost %100 to ANY destination if cost is over %100 TW.
If TW is not %0, you should still be able to travel to any destination at an S/HHP expense to prevent being stuck in BFE.