Beeswax does indeed make for a slightly harder bar of soap . . . up to a point. At about 7% + it actually can begin to soften the soap. I don't know why. Perhaps Dee Anna or another chemistry whiz can explain the reasons.
I use beeswax and honey in all my soaps; as a beekeeper, it is my "signature". (See my User Name) But it's certainly NOT necessary to a soap recipe at all. I use wax at a rate of 1-3% for all but one recipe. I like it in recipes that have a lot of softer oils, like nut oils or avocado, etc. Some people use sodium lactate to stiffen a bar. Or salt, brine, coconut oil, palm kernel oil, lard, etc.
My warning for you is about the form and prep of your beeswax. If it's not been melted, strained, and/or filtered, you will need to do it yourself. It's not difficult, but it is messy, and you will need to dedicate that pot to permanent beeswax use. Beeswax melts at high temps, (140 F) and in block form, it is . . . challenging to shave/chip/hack of the small amounts you need. That's why the pastilles are so very popular. I invested in some candy molds that make dots or kisses shapes, and hold about an ounce. I pour my wax in those and let them harden, then I have a supply of 1 oz dots to use as needed. Most of my wax goes into candles, frankly.
Beeswax pastilles CAN be safely melted in the microwave, but it is a hands on process. Zap for 1 minute, stir for a minute. Repeat. Do NOT set for several minutes and walk away! (See Anne-Marie at Soap Queen for what can happen) I just mix it in with my other oils and melt. They are usually the last things to liquefy. If you're melting a block, use a double boiler.
As for charcoal, wax will not interfere with the properties of the charcoal, it will just mean you soap at slightly higher temps (or the wax re-solidifies) and your bar is a bit harder.
Unless you are serious about it, you are looking at a lot of work, due to the form your wax will be coming in. (I assume a 1-2 pound block here, as you'll be getting from beekeepers working the clover fields.) In your place, I'd buy the pastilles from a soap making supplier. For instance: A 2 pound soap recipe of 31% coconut/palm/olive oils, plus 5% castor oil, plus 2% beeswax, will use 0.64 ounces of beeswax. That's about a generous dozen of the pastilles.
Having said all that, *I* would really love to have access to your suppliers -- PM me with details on how I can buy 10+ pounds from them, please!
And my usual caveat about waxes -- THERE IS NO SUCH THING AS AN ORGANIC WAX, soapies. No matter what the label says (ignorantly, or fraudulently) the USDA does not label waxes, period. They label oils that might or might not be made into waxes, but do not imply organic in the finished form. By the time oil encounters hexanes and other nasty stuff to be made into wax, it has no acquaintance with anything resembling organic. HOWEVER, if it comes from outside the US, and the supplier claims (ignorantly or fraudulently) that it is organic, USDA will grant them that label. Grrrrr. {Pet Peeve!!}
Good Luck
~Honey Lady~