Hello, i have a couple of questions .....
1) What happeneds if white russian figure is destroyed?
It is placed with your other dead/unbuilt figures ready to be built again. So in other words it works exactly like any other of your army figures. The reason it is white is that you can never know which of the four plastic colours (five with the expansion) you're going to play with as the Russians.
2) Does scouts harvest coins each turn?
No. You simply have one coin more as long as you have a scout standing on it. If your scout moves away or is killed, you loose the coin.
3) Does scouts harvest culture tokens without devoting in arts in a city?
No. Only cities can produce culture tokens. The scout can only help the city to gain extra tokens when doing so.
4)Does scouts harvest resource tokens without harvesting a resource in the city management phase?
Again, no. Scouts can only help a city by letting it gain an extra, temporary, square in it's outskirts. Also, a city can only harvest one of the resources available to it, not all of them.
5) With tech abilities can i buy all the coins that i want?
No. All tech ablilities that let you buy coins have a limit of four coins gained. This means that as soon as you have gained four coins on a tech you may not gain any more coins with that tech. When using the expansions investment mechanic, however you may invest coins from those techs by removing one. This means that if you had four coins on the tech before investing you would now have only three coins, allowing you to use that techs coin-gaining ability one more time.