I think staking them is up to you, in the wild they have nobody there to do it so it won't hurt the plant if you don't, you just won't necessarily get displays like you're used to seeing in stores and online, the spikes will dip down more. Personally I like them that way as well, it's an aesthetic choice. I think the cutting off of the old parts of the spikes is also an aesthetic choice, just make sure you only cut the parts that are brown and dried.
I'm not an expert so maybe someone will chip in with different advice. Please post pics of the blooms when they open, and welcome