I think the hardest way to play this game would be without fast travel! Now I could do this now but I cheat because it is there!
It's been mentioned before the release of F:NV, mulled over many times on the FO3 forum last year, and generally people agreed that fast travel is a choice, you don't have to do it. The Stimpak discussion was the same, they make everything to easy on FO3, but you don't have to use them.
The whole point of hardcoe Mode though is to add genuine ingame restrictions, like having to use a Doctor's Bag to heal a limb, but I'm finding Doctor's Bags are fairly handy all over NV, I have 20+ of them in the first aid cabinet in Novac, and I let my character carry no more than three at any one time. hardcoe should make that kind of restriction I put on myself in regards to the quantity allowed in the inventory of certain items. Weight of ammo is still nerfed in hardcoe, you can still carry far too much - it should have its own seperate, capped weight allowance. Or a numerical restriction, like 60, or even 30 rounds for handguns and such.
I don't have a problem restricting myself, and hardcoe Mode for me isn't much different to how I played unmodded Fallout 3. The only real thing it has changed is in having my character consume food and water, and to sleep. But in Fallout 3 I had my character sleep at fairly realistic intervals anyway, and fatigue hasn't even been a factor for me on F:NV. I have my char carry five food types and five bottle of purified water. I'm still not using Stimpaks.
In short, Fast Travel should be restricted for hardcoe Mode, definitely, but I don't mind that it's not as it falls short of the restrictions I put on myself anyway. So it has had very little impact on the way I play. :shrug: