Rebirth of My Conlang

After discussion with colleagues in Yahoo! Conculture as well as Dirk
Elzinga, I'm making a renewed effort to develop my Gothic conlang.  Your
help will be most helpful.

I'm anticipating the following factors to influence my lang, and suggestions
and help will be greatfully appreciated:

1) A gothic group (ca. AD 200's) will isolate itself for over 1000 years in
the Azores.

2) This group will take Latin sailors with them their means to isolation.
Per Dirk's suggestion the Latin influence on Gothic will mostly be a
nautical terminology influence.  The only problem I run into with this is
the following:

I wish to make this a 'current' language, and because I'm only able to base
this language off of Wright's grammar, my lexicon is rather limited.  I'm
wondering if the lexical holes I have now will be filled by later Portuguese
borrowings, or would I 'engineer these words from Latin or other Germanic
tongues?  Could I say that the result of time has weeded out the 'original'
Gothic words I'm missing/needing, and use the Latin-descended replacement?

2) The Liturgy will remain in Gothic, propagating the Arian Heresy.
I know that this will influence sound changes, possibly creating a High and
Low-Gothic, but I'm uncertain as to the scope of this staying influence.

3) After 1300 years this group will be subjected by sea-faring Portuguese,
with a possible superstratum/substratum. relationship developping, at least
for a time, producing a similar influence on the Gothic as did the Norman
invasion of England on English.


4) I'm wondering about a flattening of the case system.  German has four,
Gothic, five, English, two.  Is there a rhyme or reason for this flattening?

5) I was thinking that a Grimm's Law change would apply to the Gothic in the
1000 year time, and possible a vowel-shift (or possibly, two)  I'd like to
keep vowel length.

6) I am interested in keeping the hwair [ p\ ] in the language.

Those are major points I'm wanting to maintain.  Thanks for your help and
suggestions!