"-that we live in an incredibly sophisticated simulation."
My only issue with this is that if most of reality is simulations, then the distinction is arbitrary. Just because we call the largest part of it "simulations" and the smaller part "reality" doesn't make them meaningfully different if they work according to the same rules.
"-I consider my theism rational although speculative."
Likewise, I don't know if you recall but I'm a naturalistic pantheist and think God is probably what the simulations are running on. I have what I believe to be good reasons for supposing this, but am content to fall back on atheism should I ever discover serious faults in those reasons.