You can also taxi around with a yardstick taped to the top of the wing, so t gives maximum drag. (stand on edge and brace with tape) The plane won't take off this way, and you get a better feel for how it will realy act making a turn on the ground at speed. (the wing will make it easier to tip over)

The Sparky SHOULD have made a good trainer... Sure it was properly balanced? The design is based on old 1930's FF aircraft and is very stable. If it was too touchy... the CG was wrong or the control throws needed to be reduced.

The Wingo will fly slower than the Sparky, and that may make it a bit easier... but it will not handle wind well. The Wingo is relatively rugged, except the nose tends to get crushed. (repair with yellow or white glue... or the new Polyurethane foaming glues) The Zaggi is more durrable than the Wingo... but isn't good for a trainer due to its shape. (harder to keep track of which way its going than either of your other planes.)

There is no good way to teach yourself. #1: The plane will probably not be properly trimmed to fly straight without constant input from the pilot... #2: You have no experience, wo you won't know how to correct when the plane goes other than where you expected. It is possible to succeed... but you'll break a lot more airplanes without help.

A 5 to 10 ft crepe paper streamer behind the airplane will tend to stabilize it a bit... That sometimes helps people that are trying to teach themselves.