I can't answer all your questions but regarding the Autoglym, you should know that you'll only get 3-5 soaks per bottle.
With the shipping costs, that makes it a very expensive method for you.
I would recommend you continue using the mirror slide and maybe only use the Autoglym once a month to get the lace really clean.
Have a look at this and see if you can find a more local supplier:
http://www.autoglymprofessional.com/Trad...butors.asp

As for ORWG, I used that and got a 2 week hold but would have to touch up the hairline at least a couple of times in that period.
Other white glues to consider are Ghostbong XL and NEX GEN, both available from Hair Direct.
The last 2 are meant to withstand oil AND sweat, whereas the ORWG is mostly about oily scalps.
You can also combine it with products like NO SWEAT that can keep your scalp dry whilst the glue is setting.