RE: steerable nosewheel
I actually flew a plane for a whole day that didn't have a steerable nosewheel. But, it did castor on its own, so the rudder remained effective. I believe that you are talking about fixing it into place--not a good idea. I wouldn't even recommend a castoring nosewheel. I just did it one day because my linkage broke at the field, and I wasn't ready to go home. I also had enough experience to handle the situation.