Sduibek,
First of all, congrats on what you have managed so far and best of luck in going forward.
Actually, I have been following NMA for years now, but the discussion of your "mod" is what prompted me to finally register.
So without further ado, here go my two cents:
1. As many have pointed out, it's important to separate bug fixes, restoration and modifications or add-ons, especially when they alter game mechanics. We all want bugs fixes and most of us want the content that was omitted from the game to be restored (and I'd add as long as it makes sense and doesn't unbalance the game mechanics), but mods and add-ons are very tricky.
My honest recommendation would be not to do it unless it's done properly. For example, Fallout 2 New Vision was a proper modding attempt (in fact, IMHO NV is much better than the vanilla - I wish there was a way of merging NV with the F2RP...), because it introduced changes in game mechanics and in content that went hand in hand to create a new experience. This is, I think, the test that a mod has to pass: it has to create a new gaming experience and this experience has to be enjoyable too.
By contrast, I'm sorry to say that, say, adding a merchant and an elder to Shady Sands (who gives you a hunting rifle and armor because you say you are going to kill the rad scorpions) is a bad move... it's sort of like Greedo shooting first
I mean, what's the point of these characters? They don't add anything to the gaming experience; they are not interesting to talk to, they don't pose any skill challenge, not to mention that using them feels sort of like cheating... I apologize for being this blunt and bringing up Greedo, but it's solely intented to make a point
2. Regarding your proposed "survival" mod:
IMHO, the total lack of the "survival" gaming dimension is the main shortcoming of the whole Fallout franchise (including the bastard attempts of F3 and F: NV). Fallout mechanics have always focused on the dimension of conflict resolution in a post-nuclear society (which in F3 and F:NV is reduced to killing stuff in slo-mo), and the survival aspect has been completely ignored (at least until F: NV, and it's hardcore mode, which is a joke; the "survival" skill seems to have been based on the first-hand experience of a bachelor who recently moved out of his parents house - serioulsy, what was all that stuff with cooking recipes?!). This shortcoming is especially unfortunate because most of the conflicts in a post-nuclear society ought to be precisely related to survival...
Having said that, I think that it would be impossible to mod Fallout to properly include the survival mechanics. Stuff like making the PC carry a canteen is simply annoyining, same as say making constant skill/stat checks to see if something happens to the PC while travelling. To properly reflect the survival aspect and make it fun, some all-reaching and serious mechanics would have to be included, which the game simply can't handle. For example, think of the following:
(a) Travelling should require carrying supplies; and I don't mean make the PC carry a dozen iguana bits and make sure he or she has to "use" one every day - it's not fun and it's not realistic. What this mechanic has to reflect is that the PC has to carry supplies worth x nutricious value (taking into account the PC's relevant stats and skills), such supplies having a weight of w (that reduce his speed by y) and a cost of c (which is, for example, proportional to x and/or inversly proportional to w). Basically, that travelling further and/or faster is more expensive and/or requires better stats. I'm not saying that this "the" mechanic that should be used; what I'm saying is that some sort of mechanic in this regard would have to exist.
(b) During the travels, the PC has to sleep at some point, at which time he or she should be vulnerable to attack. Some decisions have to be made as to where to set camp, whether to invest time in setting up defences... or whether to crawl under a rock and hope that nothing happens.
(c) There are decisions to be made regarding whether to travel at night or at day (e.g. it's hotter at day and you are more likely to be spotted by humans, but your avoid the nocturnal predators), following known trade routes or not (e.g. the trade routes are faster and you are more likely to find other travellers, but do you want to find them?), travelling by yourself or with others (e.g. unless you are a ranger, travelling by yourself through the wasteland shoud be suicidal), etc.
So, in other words, travelling between settlements should be a dangerous and costly enterprise requiring a bit of planning and foresight and to properly implement this survival experience requires a set of over-reaching gaming mechanics; otherwise it will only be annoying.
I don't think that any of the Fallout games can allow for the implementation of the necessary mechanics; at best you can introduce some annoying requirements that might initially seem like adding to the atmosphere if approached with sufficient enthusiasm, but that will soon derive into a boring routine. I'm thinking of F: NV and drinking out of an irradiated toilet, trying with all my might to conjure up a feeling of desperation, despite being fully aware that I would have to drink from another 100 irradiated toilets before my character would suffer a -1 to some stat or other...