#1
hello, I bought a resonator guitar/ not a Dobro sadly considering my application is coming to need a square neck more and more, in my progressing of learning this instrument Ive come to a couple road blocks,
the first is open the tunings all together, i play harmonica and an used to meshing tuning and keys to fit properly in off key, "live tuning"?not entirely sure on the vocab, so there is always the ability to step up or down in tuning whole steps half steps and minors by tuning your third or second string down depending on tuning, the question is, how do i learn what goes where when tuning to a key, im looking for a chart of some sort i guess, keys-->tunings

the second question is, when sliding up scales when is it appropriate to up the strings or up the fret board, the Technics seem limitless for most applications, its almost a method of voicing out the melody, with this in mind where does the the basis of chords come in while using a single string at one time and at least 2/3s of a solid barre the rest of the time, i under stand the whole chord building methods, triads built on a root, a 5th sometimes a 7th so where does that apply to a slide, do i hit a single not, hit a root and slide to a 5th ect,

this method seems to be very uncharted
thank you
#2
I'm not sure what you are asking in the first para, but this is the site I use for finding chords in alternate tunings:

http://www.looknohands.com/chordhouse/guitar/index_rb.html

This allows you to set the tuning and see how chord intervals fit into that tuning.

Open tunings like open G and open D are tuned to major triads, so in open D, for example, barring the 5th fret gives a G major chord. You can use bar slants to get other kinds of chords, and learning how to imply chords is an important aspect. Eg, to imply Em, you might use E5 moving to G major.

If you use the 6th type tunings common in country music you can get a major and a minor chord on the same barre by choosing the strings you play. Eg C6 gives Am and C major triads on the open strings.
#3
Here's a page dedicated to "lap steel" which has a great deal of information on the wide variety of tunings in use:
http://www.well.com/~wellvis/tuning.html

This is geared to lap steel but fully applicable to your use.

If you are talking about re-tuning "on the fly" and such.... Allow me to suggest that you seriously consider the steel guitar or "pedal steel". This is a VERY complex instrument, what with two necks, foot pedals, knee levers, etc, etc. However, a good steel player can play literally anything.....