Pick a design that actually gets read.

Ten to fifteen years in detail. Older jobs get one line each, or nothing at all if they don't help your case. That's not hiding anything: a résumé argues for one job, it isn't your life story.

Not in the US or UK. Plenty of employers there bin résumés with photos to keep bias out of screening, so it can genuinely cost you the read. Different elsewhere, much of Europe and Asia expects one.

No. It tells them what you want, which they already know. A two-line summary is worth more, and only if it says something specific: what you do, at what scale, what happened as a result. If yours says "motivated professional seeking growth," that space is better spent on a bullet.

Yes. Drop the short ones and the irrelevant ones. Just watch what gap you leave behind, a one-line entry is easier than explaining a silent two-year hole. And a background check may show your history anyway.

Nowhere. "References available on request" spends a line saying something everyone already assumes. Keep a list, ask the people on it first, hand it over when asked.

Tweak it, don't rewrite it. Keep one strong version and change the summary, the order of your bullets, and which skills you lead with. Starting fresh every time is how typos get in and how people quietly give up.