Yes, Nokia 7 Plus does have the OTG support.
Yes, Nokia 7 Plus does have the fingerprint scanner.
Yes, Nokia 7 Plus is made of series 6000 Aluminium.
No. Despite a bigger battery and the Aluminium Alloy body, Nokia 7 Plus does not have any abnormal heating issues.
Great battery life, immersive display, solid design, and software at its purest, that's the Nokia 7 Plus for you.