[QUERY] Hard disk internal wear n tear

I’m using a WD my passport 1TB ext. portable hdd for 1+ year; few days back I bought a sony HD-E1.
I use these hdds for back up purpose, storing good movies and watching movies from.
My pc/laptop remains turned on for 3+ days.
While I’m away from my pc/laptop, i put the system on “Power saver” profile.

well, in my windows power settings for “Balance” profile, the time for “Turn off hard disk after” is 10 mins; 
and in “Power saver” profile, the time for “Turn off hard disk after” is 5 mins.
Is the time in these settings configured correctly??

Now i want to know,

1. Is it okay to leave portable ext. hdd connected to pc/laptop, while the pc/laptop is on for whole 1 or several days?
2.  Will it make large difference in wear n tear of internal disk and read/write head, if i remove ext. hdd, while not in use??

I’m also wondering,

if there’s any way of turning off the power to ext. hdds while they’re not in use, and turning them on again without detaching/attaching the usb cable from usb port.

The passport should go into sleep mode when not in use, you can install smartware to setup the sleep time. 

Could someone answer Questions #1 and #2 directly instead of sidestepping them?