Yahoo Answers always starts focussed on 'Discover' , and I have to waste time moving to 'Answer'. Is there any remedy?

No, although users have requested (in the feedback forum) to have that changed. Thus far, no action has been taken by Yahoo/Verizon.  You could try bookmarking the "Answer" tab in your subcategory of choice, so you'll be taken straight to there when you access YA, but when  you change to another category/subcategory you'll land on their "Discover" tab and have to make that extra click/tap to get on the "Answer" tab.

There is no setting for that. You just have to click on the Answer tab each time.

Yes there is (Windows / Linux / Mac).

Install Tampermonkey extension for your browser and then install this script : https://greasyfork.org/en/scripts/407048-yahoo-sho... 

Unfortunately no your gonna have to Switch to Answer Every time by Default Yahoo Always places you under Discover Section first 

I concur..........annoying as hell.