I finally decided to give the original Fallout a try. Since I never manage to create a character that's good at something and always get beaten up, I decided to just go with Max Stone. So far I've been to Shady Sands, Vault 15 and Junktown but still haven't found anyone with information about the water chip.

I read somewhere that if the character's INT stat is too low, it won't be possible to speak to some characters to get quests and such. Example: In Shady Sands, the village chief told me to ask the village doctor about information on dealing with the RadScorpions, but the doctor has nothing to say about that. Bug, or consequence of poor INT?

It seems silly that the devs would offer a pre-made character that can't even get through the game. Any suggestions?

Max stone has 4 int which enough to speak properly. There are a few extra dialogue options which depend on int and with high speech skill you're more convincing but you you won't miss much because of missing a few dialogue options, no need to waste resources for improving talking now. There are drugs which increase int but I wouldn't bother taking them.

You were sent to retrieve a water chip from another Vault, you visited Vault 15 and noticed there isn't any now it's time to search elsewhere, you'll meet people who know more if you explore more of the world.

I might have to play the game again later with another character. It seems there's quite a few quests I can't do on account of the limited dialogue skills. But I've already found another possible location for a water chip, thanks!

Is it possible to get better dialogue options and in turn more quests just based on character level alone, or does it all depend on INT & Speech?

The cuttoff for a stupid character is 3 INT. 1, 2, and 3 int give the exact same dialog options, while 4+ pretty much unlocks everything except for a few rare options (like with ZAX). You should definitely try a stupid game at some point though, it's a pretty fun experience. It's not a good idea for a first playthrough, though.

For the doctor, you need a Radscorpion Tail before the dialog option will open up.

There's not a single extra quest you get if you have 10 instead of 4 int. You only get a few extra dialogue options which are nice to have but aren't crucial.
A typical example: If you come to Junktown at night, you get one chance to ask nicely to be let in (IN 5 and a Speech check), or you'll have to wait until morning.

Max Stone might be too dumb to get quests but at least his muscles get results :).

Some quests just doesn't seem to be able to do. For example, I can't bust the Skulz in Junktown. Either I help them but the entire town turns against me. If I refuse to help them, they'll attack me, and when I kill them the guards turn against me even in this case.

I'm really enjoying the game though. The difficulty is just right compared to Fallout 2 where I got my butt kicked every other fight. Might just have been my poorly designed character though.