whoa! You posted your songs for critique, and people have actually been pretty nice - critique and criticism are not the same beast.
I can't speak for the others, but I listened blind - no preconceptions, as I always do and here, we can be presented with all kinds of material. I hate rap, thrashy metal and a few other genres, but I can appreciate what goes into them. I never comment on lyrics, because I never listen to them - just the music. In my entire musical life I probably only noticed the words on maybe half a dozen songs. I wa planning my funeral music the other day, and discovered one song I 100% wanted I cannot use because of the lyrics. I loved the song, but never realised the words would be very inappropriate.
However - what I must disagree with you about is the suggestion that for somebody to comment, they have to prove they have expertise. This is totally NOT how it works. If you get a number one hit song, very few people who listened to it have musical bones. Even fewer are songwriters themselves. I cannot dance a step - I have no coordination, but this week I've said no to three prospective dancers, and commented critically (in writing to the producers) why they are not suitable. I am extremely experienced at watching and understanding and being able to evaluate, but I could not demonstrate these skills at any level at all.
Your songs are OK. Your playing is OK. Your arranging is perhaps lacking a bit because you've not noticed little conflicts, rules of harmony clashes and tiny things like that - that jump out and say "Warning Will Robinson". It doesn't matter because you said your interest is not in recording but the writing - so the technical stuff we can set aside.
I have not detected criticism, just honest critique - which is what you asked for. Not liking the result isn't really our fault - and may be representative of what the public might think? Who knows?
Harmonica sample pack as in VSTi - you mentioned one real harmonica was a Heins. Never heard of them, but I have a Hohner - a chromatic one, and in my part of the world, most decent players use them. I'm sure yours is a wonderful instrument. I can't make mine sound nice, because I'm not that proficient. Having a nice instrument won't make my playing put me in Larry Adler's league by a very long way. I'd probably NOT play mine for a recording, I'd use one of the sample packages I have, or maybe even the synthesised one in the Halion Player bundled with Cubase - that works pretty nicely with mod and pitchbend.
Kurth - you are very welcome on this forum, but I have to say nobody has criticised, only attempted to assist with comments we thought you actually wanted. Pretty well all of us are not afraid to post up links to our own stuff, and sometimes the results that roll in are unexpected, but personally, I would rather somebody here tell me my XXXXXX (insert instrument of choice) sucked, than be told it on Youtube by strangers!!