Need "bug free" template for online sales marketing

We’re not picky.
Need something “bug free” or nearly “bug free”.

We are looking for a simple to use WordPress theme that offers the following:

1. Ability to add:
Menu
Audio clips
Video
RSS feed
Work with Livestream
Works well with Optimizer Press on a subdomain
Handles aweber okay

I’m curious what you all are finding with WordPress. I knew it “well” about four years ago – up to when the big programming shift required the SQL changes. All my sites crashed, my client sites crashed, it was a mess as we couldn’t figure out how to fix the problems.

I’m being told to return to WordPress and really don’t want a repeat experience.

Can anyone tell me something about the reliability to WordPress these days and maybe how we can better prepare for tech changes so we aren’t wiped out like last time?

Thanks!