Can you use different rail cars from different Bachmann sets of the same scale?

[newtotrains2016]

I would like to run this set
http://shop.bachmanntrains.com/index.php?main_page=product_info&products_id=5915

with the 3 rail cars from this set..
http://shop.bachmanntrains.com/index.php?main_page=product_info&cPath=258_269_270&products_id=4596

Would that work? Or would I need a larger power supply?

Can I use both (or some) of the tracks from the 2nd set to have a larger track?

Can the track be slightly raised in one part (the back of tabletop layout) or does it have to be on a flat surface?

These would be used during Christmas to go around a Dept. 56 Chritmas setup, would these sets be a good choice in that situation and for a beginner?

Thanks

[Flare]

Would [combining two sets] work? Or would I need a larger power supply?

That should work, I imagine one locomotive can pull all of the cars using one of the included power supplies.

Can I use both (or some) of the tracks from the 2nd set to have a larger track?

The tracks in both sets should be the same.  (Nickle-silver rails on gray roadbed)  If one set happens to have steel rails on black roadbed the two will still connect with each other.

Can the track be slightly raised in one part (the back of tabletop layout) or does it have to be on a flat surface?

Part of the track can be slightly elevated, but ease the train into and out of the grades or it might uncouple itself.

These would be used during Christmas to go around a Dept. 56 Chritmas setup, would these sets be a good choice in that situation and for a beginner?

I'm not familiar with Dept. 56, but I did check their FAQs and they say HO scale trains are almost the same scale as the majority of their pieces:  https://www.department56.com/category/customer+service/faq.do#train

As for being a beginner, just about any HO set is good because it's popular enough that replacement parts are stocked in most hobby shops.

Additionally, Bachmann has videos on Youtube demonstrating how to set up and maintain their trains.

HO scale part 1:  https://www.youtube.com/watch?v=na5HRxZAmaI
Part 2:  https://www.youtube.com/watch?v=Ru1UP-Ao2rA
Part 3:  https://www.youtube.com/watch?v=OtW8Gx_WxL4

You should also invest in lubricant(s) for the locomotive as mentioned in the third video.

[jbrock27]

That should work, I imagine one locomotive can pull all of the cars using one of the included power supplies.

Perhaps, on level track.  The locomotive involved is more critical to pulling strength and ability than the power supply. 

The tracks in both sets should be the same.  (Nickle-silver rails on gray roadbed)  If one set happens to have steel rails on black roadbed the two will still connect with each other.

They are both the same, but both are steel.  Something, beginner or not, I would avoid spending $$ on purchasing.  Better to go with buying the nickel silver track.

It pays to shop around, for everything, track, lube, cars, locos, everywhere, on the internet in stores.