I would say hotter than a habanero but pretty close to it. As far as being unstable, grow it like you would any other pepper. Being unstable genetics just means they may look a little different than described or expected.
I grew it probably 7 or 8 years ago. Was upper heat level with good flavor and pretty prolific. Having said that, being 7 or 8 years ago, it’s likely your outcome will be different than mine because of it being a hybrid and I’m sure its genetics are still quite unstable.
Green and red Anaheim yes but the yellow and orange ones could possibly be Marconi peppers. Is there any heat to them? There are also countless hybrids out now which makes identification very difficult. It’s also common for stores to intentionally mislabel varieties and hybrids as something more...
Aphid “proof”, no. But I have definitely noticed some of my pepper plants will get attacked relentlessly by aphids and others, not so much. I wish I could be of more help recommending what varieties would be best but I’ve never compiled a list.
From my experience of having started thousands of seeds over the years, if they start slow and scrawny, they’ll never be strong and vigorous plants. I shouldn’t say never actually cuz I’ve had a few occasions where the under-performers kicked it into high gear and did well but it’s not the norm...