1.) While following the general guidelines as to ratios of makeup for the oils, can I substitute any oils in my recipe as long as the total oil weight is the same? IE my first batch was 72% olive / 25% coconut / 3% castor. Could I have made it 52% olive / 30% avacado / 25% coconut / & 3% castor without issue?
No, you'd have to recalculate because the lye amount would be different.
2.) He talks about shelf life of an oil. If I use an oil that has a 6mo shelf life, and it takes 1.5-2 mo to cure before selling, does that mean that if the buyer doesn't use it in 4 mo then it will start to go bad, and I'll look like a jerk?
Saponification helps to prevent oils from going rancid as long as you don't have too high of a superfat. I have some bars I made from over 2 years ago that are fine. However because I didn't get around to using up the remainder of two of the oils, these oils went rancid. I was just sick that I had to toss these oils. I know people have mentioned having soap that is quite a few years old that are still fine. You also wouldn't want to use too large of a percentage of an oil with a short shelf life.
3.) on Olive oil he said "Olive oil soaps are very moisturizing, make hard, white bars of soap" and in coconut oil he says"[coconut oil] also makes for a very hard, white bar of soap." yet my soap is relatively soft (I realize its only a couple of days old) and somewhat of a creamy yellow. What did I miss?
People have mentioned different types of olive oil produce different coloration in soap. I used refined Grade A OO and my soaps have never been white. They tend to be more of an off white or cream color. Someone mentioned EVOO can turn a greenish/yellowish color. I don't remember if pomace causes a discoloration or not. I wouldn't worry about it unless you really want a white soap. If you want it really white, you'd probably have to add some titanium dioxide.
Olive oil also takes a long time to cure but eventually it will get hard. Some people have mentioned curing at least 3 months, some have said they prefer to cure even longer so the lather improves. Don't worry if it stays soft for awhile. It's normal for high percentage olive soaps to be soft in the beginning especially if you used a full water amount. Castor oil also makes for a soft soap but generally isn't a problem unless you use a large percentage.
There is a learning curve to soapmaking but by tweaking recipes and comparing the different batches, you'll start to learn what each oil brings to the soap. You'll also learn what you prefer. For example, I found I prefer a lower CO percentage, a higher SF and I like to cure my batches for about 6 weeks. But this is just my preference. BTW, if you're thinking of selling someday, here's a link to a thread which discusses on how to know if you're ready to sell. http://soapmakingforum.com/viewtopic.php?f=17&t=17621
Also, your soap looks very nice!