Buttercream adventures

I used Sharon's Zambito's buttercream recipe which is a crusting version. It crusted very nicely! I used Crisco even though her recipe calls for high ratio shortening – which is supposedly better tasting and mixes better with the powdered sugar. You can only get online and have yet to do that. I am also in a dilemma about trying to make it a bit healthier
As of now my experiences with buttercream have been:

• True crusting recipe but added meringue powder and cornstarch. This crusted very easily but was too crunchy the next day.  It was a recipe from Sewsweet...it was great to work with but will perhaps lower the cornstarch amount next time.

• Tried to make it again on October 24 – a very humid day. Needless to say, a terrible buttercream day! It was very spongy and full of holes. It even make a sucking sound when it was in the mixer! I found out one needs to add a bit of liquid, but not too much
• Buttercream by a Chef – two sticks butter and sifted powdered sugar. This tasted great but still too soft.
• Sharon Z buttercream, but this time used 6 oz of Crisco, 12 oz Spectrum Organic Shortening, 2 lbs. of powdered sugar, and 5 tbs of powdered coffee creamer. This had nice feel, but once again did not crust... Too much liquid? Was it the organic shortnening? Was it just a very humid day?

My trouble right now is finding a buttercream recipe that will work well and trying to find flavors for fillings. Even though I've done a ton of research, it is very hard to know exactly what to do.
I ended up making another swiss buttercream that was delectable but it was very soft. Knowing that the wedding will take place in Texas in September, I think that buttercream might literally slide off the cake before we get it to the reception site!!!  But this type of buttercream might make a very good filler.

In limbo right now...