Great points.
25+ banned accounts here, because I like to test different botting practices and push the limits and see what I can get away with. So what I've observed is that you can get away with chatting IF you pause the bot, talk in cc or whatever and then click to resume botting.
However, regularly chatting DURING botting will get you banned. Especially because a lot of the bots here seem to use the arrow keys to move the camera, so if you chat away during that, it's an obvious red flag. Pause the bot, then chat, then play. Keep the mouse and keyboard inputs blocked if you care about the account.
Also I wouldn't do any skills by hand that you've heavily botted. Your play style most likely won't be similar to the bots, this is especially true with combat bots. Two very distinct playing patterns is an easy giveaway.
And account age is irrelevant as long as you don't bot like a retard and go 12+ hours a day with no breaks. You might get away with more on older accounts, but nothing is guaranteed.
I also bot during the Jagex office hours daily (EU timezone), in hotspots and in f2p as well and get away with it easily. So I think people keep over inflating the importance of avoiding it.
1) Just keep your hours human like (I've found 4-10h botting per day to be the sweet spot with small breaks every 1-3h and occasional afk'ing);
2) Have a name and combat level that doesnt negatively stick out in a hot spot and scream 'bot'. And don't look like the default bald character;
3) Use a bot/setup up the bot so it looks as human-like as possible. Eg. I see a lot of people set up mining and woodcutting bots (on accounts that obviousy weren't meant for suiciding) incorrectly and they stand out like a sore thumb. Observe what your bot is doing and test different locations/radiuses before you allow it to work on it's own for extended periods of time.
Have all three done correctly and you can bot at any hour you want without worrying about bans. I could keep on going, but this post is long enough I think lol. I could write an essay at this point on the things I've personally learned and things I've found to be true/false about some of the recommendations here and elsewhere...