ct03si,
Since you've been with us for a few days, I'm sure you've seen threads about trains that jump the track, cars that randomly uncouple, and other instances of trains behaving badly.  These events are often caused by uneven track.  If you throw a piece of plywood on a couple of saw horses, the plywood will warp, I promise, resulting in unreliable operation.

Please take time to frame your platform.  The process is very simple, much like framing a wall.  I use 1X4's from the local home improvment center, and assemble the parts with utility screws.  Legs can be 2X2's

Extruded foam insulation two inches thick can support itself better than plywood, but still needs to be framed.  If I were using foam, I'd set it down inside the 1X4's to protect the edges and put the cross members on their sides so there are no edges to dig into the bottom of the foam.

Go to your local hobby shop and buy a "how-to" book for beginners.  Kalmbach (the Model Railroader folks) offer an extensive selection of books including one that just covers building benchwork.   Hope this is helpful.
OldTimer

I wouldn't risk it...I looked under the hood of my wife's sewing machine and didn't see any plastic.      Bachmann and Labelle both sell suitable lubricants.
OldTimer

Good for you!!!!      Fixin' stuff is the best!!!

The last few pages of every issue of Railroad Model Craftsman and Model Railroader consist of a (bricks and mortar) hobby shop directory by state.  Most hobby shops are glad to special order items they don't have in stock.  You may be asked for a deposit up front for expensive items.  If you make all payments with a credit card, you have some extra protection.

As a long time e-Bay user, I encourage you to try to solve your problem through e-Bay.  There is a Resolution Center that you can reach through the Customer Support link on you My e-Bay page.  If you and the vendor cannot come to terms and you really got taken advantage of, you should leave negative feed-back.  Make sure that your communications with the vendor are done through e-Bay so there is a record.  Hope this helps some.
OldTimer

One other thing you can do is file the end of the rail a just a little to remove any burrs that may be there and also to help the rail joiner get started.  File parallel to the rail, not across it.
OldTimer

The National Model Railroad Association (NMRA) has a wonderful set of articles for beginners.  Check it out here:

http://nmra.org/beginner/consist.html

Good luck and welcome to a great hobby.
OldTimer

Don't mess with success, as they say.  See if you can find an old, inexpensive, train set power pack, hook up your radar tower to the variable DC outputs, and run your radar at about 1/2 throttle.   Adjust as necessary.   
OldTimer

Zamak is an alloy of zinc, aluminium, copper and magnesium. 
OldTimer

Airfix, a British company, used to make an extensive line of 1:87 military models; tanks, trucks, APC's, etc., but I don't recall specifically if they made any aircraft in HO scale.  I know I built enough of their 1:72 airplanes.  I think the series was called "Minitanks."  Anyway, that's one more place to look.
OldTimer

Excellent job, Jonathan.  It really turned out well.  Thanks for sharing.
OldTimer

Cary Locomotive Works produced boiler castings for several steam locomotive chassis as well as castings for diesel bodies.  In those days we weren't quite so discriminating and the castings were generally considered to be a step up.  I think that Bowser eventually bought Cary but I could be mistaken. 
OldTimer

I suspect that the uncoupling problem is due to abrupt vertical curves on your bridge set.  No coupler is going to compensate for uneven track.  Another possibility is that the engines are running down hill at uneven speeds and creating enough slack and misalignment that the couplers can work loose.  Having said that, Kadee has an extensive web site.  Look here:

http://www.kadee.com/index.shtml

On the site you'll find a conversion chart to help you pick the right model of Kadee coupler for your application.  While you're at it, buy a coupler height gauge (Kadee part # 205).  Hope this helps.
OldTimer

Several companies make modern structures.  Walthers has a few.  A company called Pikestuff has modern warehouses, office buildings, etc.  Here's the Pikestuff link:

http://www.rixproducts.com/pikestuff_listing.htm

Scroll down to the HO section.

Faller has your wind turbine. 

Hope this helps.
OldTimer

Can't be totally sure without a picture, but I'm about 99% sure it would be a track cleaner.  The way those usually work is that cleaning fluid drips from the tank onto the pad and as the pad rubs over the rails, it picks up dirt.  I suspect you'll find it is not real effective.
OldTimer

Atlas sells a number of electrical parts that support a control system called "common rail cab control."  It is cost effective, easy to wire and essentially bullet proof.  Most hobby shops have a collection of Atlas track plan books that include detailed wiring instructions.  Once you grasp the principles, you can easily wire ANY DC powered layout of ANY scale for dual cab control using the Atlas electrical components.  Look here:

https://secure.atlasrr.com/mod1/items.asp?Cc=HN862&iTpStatus=0&Tp=&Bc=

Hope this is helpful.
OldTimer