Issues with leipzig and glossaries used together

I couldn't replicate the spacing issue around the SG, so this answer might not help you with that.

The go.PSTpastpst issue is related to the usage of the obsolete glossaries commands \defglsdisplay and \defglsdisplayfirst in leipzig.sty.

Here is what is in v1.0 of leipzig.sty on line 128:

\newcommand*{\SetLeipzigDisplayStyle}[1]{%
    \defglsdisplay[#1]{\leipzigfont{##1}##4}%
    \defglsdisplayfirst[#1]{\firstleipzigfont{##1}##4}%
}

You should create a copy of leipzig.sty, save it with a new name, and then change the above lines to the following. You will then need to load the modified style file instead of leipzig.sty.

\newcommand*{\SetLeipzigDisplayStyle}[1]{%
    \renewcommand*{\glstextformat}[1]{\leipzigfont{#1}}%
}

This gets rid of the obsolete command errors and also solves your go.PSTpastpst issue.

At least as of the June 16, 2017 release of leipzig, this no longer seems to be a problem. You just need to use the glosses package option. (This is explained in the “Multiple glossaries” section of the documentation.)

\usepackage[glosses]{leipzig}