It hard to tell if it will work for YOU.....
Everyone has different tastes, a spice combination you like, might be unpalatable to someone else.
If you want to "wing it", just throw everything in and see what happens.
Most recipes have one or two ingredients. When you go beyond that, the variability of the ingredients makes it difficult to predict the end result.
A better approach would be to make a base mead, then go get a case of quart jars.
Place your finished mead and individual spices/flavors in the jars and let them sit a while, then start doing some taste tests and blending trials.
Keep good tasting/blending notes and don't try to do all your taste/blending trials at one sitting.
I've read that 2 tablespoons of cracked black pepper/gallon in secondary is a good starting amount to try, but I've also heard that half that amount can overpower a mead. The freshness and type of black pepper you are using will make a big difference.
Using cold brew coffee in primary may work, but the usual method is to use whole beans in secondary. I've read that low-acid varieties are a good choice, but I haven't tried adding coffee to a mead yet.