I'm sorry to hear about all the issues you've been having with your car
Like TiGray said, it comes down to your ability to do your own repairs, and the amount of "old age maintenance" that he calls it that the car will need.
My biggest concern with your car is from the sound of how the previous owner did not care for it as they should have. This leads me to believe that you might be in for a pre-cat clogging and V6 self-destruction. The V6 models are notorious for slowly eating themselves away, and 150k is when many of them see their last drive. My V6 was at about 142k miles when I got rid of it, and I had a handful of things breaking on me like you've had. I decided to not dance with the devil since I have very limited knowledge of cars and replacing engines, so I sold it before it got worse.
That being said; I spotted my car about 8 months later being used as by a college individual. No idea how many miles they had put on it, but it was still going strong from the looks of it. I knew every chip and scratch on that car, so I am positive it was mine.
Both of those mechanics are correct. The car could die on you tomorrow, or it could last another 5+ years without any problems. Unfortunately, that can be said about just about any 10+ year old car that's been used regularly.
All said and done, if your budget allows for it, I'd look into getting a pre-owned 2nd or 3rd generation 6 and sell this one while it's still going strong for you. You can probably get about $4k for it, and that's a nice chunk to put down on a new car. Don't buy new, it's not worth it unless you plan to keep the car 10+ years like I hope to do so