they (~ 30 - 40 trillion and more), but anything is also okay

~ 20 years

yes (why not?)

s͟u͟s͟t͟a͟i͟n͟a͟b͟i͟l͟i͟t͟y͟, c͟r͟i͟t͟i͟c͟a͟l͟-e͟n͟g͟i͟n͟e͟e͟r͟i͟n͟g͟, v͟i͟r͟t͟u͟a͟l͟/digital t͟h͟i͟n͟g͟s͟, d͟-i͟-y͟, c͟y͟b͟e͟r͟/b͟i͟o͟/s͟t͟e͟a͟m͟ p͟u͟n͟k s͟t͟y͟l͟e͟͟, l͟o-f͟i͟/ l͟o͟w͟-s͟p͟e͟c͟ t͟h͟i͟n͟g͟s͟ (a͟n͟d͟ i͟d͟k͟ ˘⌣˘)