What's Wrong with These Tones?

I'm turning one of my oldest languages into a tone language.

In my scheme, tone is used to mark word classes.


Nouns and pronouns are all        hi roots, low suffixes

Modifiers are all                           hi roots, high suffixes

Verbs & Postpositions                lo roots, high suffixes

Other word classes                      all low



These tones, together with pure vowel/diphthong alternations, mark
subclasses of words like common-case, genitive, locative nouns, etc.

Only stressed syllables have tones;   unstressed syllables have so-called
"neutral" tone, and the only vowel sound permitted in an unstressed syllable
is the schwa.


Is is unnatural or awkward to have words with all high tones?

In a register tone language with two tones, high and low, which tone is more
marked?

Is the scheme at all natural?

More importantly, are there reasons why it would be difficult to learn or
use in comparison with natural systems?

Jim