You probably only need to take the one full protein supplement after your workout. (One 30g supplement of protein should do you each time.) If you have a regular diet with protein in it, that should cover the rest of your needs for the rest of the day.
But no, your body does NOT become dependant on high amounts of protein. If you take more protein than your body can use, it simply gets urinated out or stored as far. And it's alright to skip the occasional day, as long as you're still getting a fair amount of protein from whole foods to maintain your energy and body composition.
And sorry, Nwheel, but most of what you said about creatine is wrong. True, creatine will cause you to retain a little extra water in your body, but that doesn't have any severe side effects other than making it a little easier to become dehydrated.
Creatine is a chemical in your muscles that reacts phosphorus to cause a turnover of your energy stores. Basically, when you use ATP (the energy compound that causes your muscles to contract) it becomes, in Layman's terms, de-energized or depleted. Creatine and phosphorus then cause a chemical reaction that will restore that energy supply.
So, what creatine supplementing does is increase the turnover of your energy stores and allow your muscles to last longer during strenuous exercise. Like protein, your body WILL NOT become dependant on creatine, and you won't lose muscle mass after you stop taking it. The only people that actually do lose muscle are heavyweight lifters and body builders who are pushing their genetic limit on the amount of muscle that they're able to maintain, and that's only because they likely require that extra creatine in order to keep lifting the amount of weight required.
Creatine also does not work as an acute, once in a while/one-shot supplement. Taking it post-workout for recovery won't really do a whole lot. Rather, if you take creatine, you need to take regular doses to maintain elevated creatine levels in your muscles. (Usually through a loading phase for a few days followed by a lower-dose maintenance phase.) As such, it doesn't matter what time of day you take it.
Oh, and creatine doesn't do much for endurance athletes. Endurance activity utilizes the aerobic energy system of the body, using oxygen to prolong constant muscle contractions over a long period of time. Creatine is used for the anaerboic energy system which is utilized when doing short bursts of muscle activity such as sprinting. (It's the energy you use for a few seconds before you start to produce lactic acid.)
