I'm a novice and it sounds complicated. You have to whip your egg white to the perfect consistency (without under or over whipping which seems hard to me) , and you have to heat the sugar/water/etc mixture to just the right temperature and I think it would be tricky adding the hot element to the egg whites. Is it difficult or is it a forgiving recipe that doesn't need to be perfect? I might make it next time I make my flan which uses the yolks, so I will have left over whites.

I don't find the Italian buttercream very difficult, but no... it is not a forgiving recipee. You must follow the instructions on temperatures quite precize.
The fun part is actually putting the hot sugar with the eggwhites, to me. It makes you feel the best scratch-baker.

I don't think it is difficult to make at all. It can take a bit of babysitting in the beginning but it is totally worth it. Look up Warren Brown's video. I have been making swiss meringue buttercream exclusively for over 5 years because I thought the italian was difficult. Once I made it the first time, I never looked back. I love them both but the italian method is quicker for me. HTH and good luck

I think many people fail the first time. I did. I got to the curdling stage and was sure I messed it up. But the second time's usually a charm for everyone.

I always make swiss meringue buttercream because I don't like the idea of making a boiled sugar syrup. I'm afraid I'll somehow drop it on me between the stove and the mixer... And I've never been good at pouring a thin stream into the mixer without catching the whisk and getting sugar strands.