Answer:
1) Small Spurs has effect only on your hero, so your hero will run faster together with your army.
-While Boots of the Mercury reduces overall travelling time so it is suited with your preference.
2) Nope, but people can plan how they plays regarding on the WW issue since Day 1,
for when you can conquer it is depend on what speed server you plays.
-It's normally 112 days for 1x server, and 45 days for 3x server.
Please PM me of your contacts for further information. 
