Forge of Empires Android Cheats and Tips

No

Yes.
Sell your older age goods buildings and build those from your current age. Using the trade system it's quite simple to trade down at 1:2 to the next lower age. If the footprint is the same (say 3x3) age x produces y per day of that age, but trades down to 2y of the previous age.
Keeping goods buildings from ANY previous age makes zero sense.

If you are successful in battle against other players in PvP tournaments, you will get medals as a reward for your rank. You can also receive medals through participating in leveling up Great Buildings. Use them to get additional expansions to the city.

When you pull up "Construction/Build" (upper bottom left) At the top Top of your Screen has; "$" for selling - "+" (with arrows) to "Move" - "0 with /" for "Cancel". Click "Move" and what you want and if you want to replace it with some thing else it MUST have the same area dimension (size) or a "Clean" area, Basicly you can Swap Items by clicking it and you will notice the piece you picked up has changed if the piece you Swap is too large or not the correct tilt, just hit "Cancel"

As far as I know there isn't. It's a pain in the ass but you just have to do it one by one