I submit the way its going is not where you want to go. I can appreciate your desire to do what you can to secure your dream, but you are in fact, doing it wrong and subsequently will probably not achieve your dream. Relax and stop sacrificing some good things in life because you think it will get you ahead, foot in the door, etc (it won't). I think it was Buddy Spike who said 69% of getting yourself that dream job is just being a good dude (and that also means being yourself, not pretending to be someone you think they want), showing a bit of aptitude and knowing when to STFU. All of that does not even remotely require you to burn through your bank account (buying a glider for example), give up on "the fun job," dump the girlfriend, etc.
You seem like the guy who will role into an interview trying to be someone you think the dudes want to see, talking about aerobatic glider flying and how you gave up all this great shit because flying means more than your own mother. If you just shitcan that approach, be 100% yourself and most of all, be humble, you'll have a FAR better chance of getting hired. You're not going to impress anyone with the approach you seem to be taking. You will impress people by being a genuine, good dude who's actions and words speak to that.
Lastly, flying anything can help you in UPT, albeit usually only slightly. Fly because you want to have fun, learn something new, etc. Don't get wrapped around the axle about instrument vs. aerobatics vs. tailwheel rating, etc. None are going to give you a magical advantage over the others when it comes to prepping for UPT. If you really want to drop 15K on a glider, go for it, but DO NOT do it because of some idea it will help you get a guard job or help you get DG at UPT - do it because you really have a passion for it (side note: probably want to figure out if you actually have a passion before buying your own aircraft...technique only).
That's my candid, no bullshit response to what I've read here. Take it as you may, but realize while there are some sarcastic responses on here, there are several legitimate responses from experienced flyers. I suggest you take that into account before continuing down the "LOL, fuck it, this is the way it goes" road.