1999 Ford Explorer problems

First post and uneducated when it comes to cars, so I hope someone can help me.

In Dec 2007 I purchased a 1999 Ford Explorer from JdByrider. It has 66,000 miles and is 4 wheel drive. At present the check engined light has came on twice. The first time I was told I needed to replace the intake manifold gasket, which I did. About two weeks later the check engine light came back on. On my first visit with the dealer/shop I told them about a grinding noise in the front of the car when I turn right (not even hard) or when I back up and turn the steering wheel. I was told it is a 4 wheel drive car and that's to be expected. Maybe it is, I'm not for sure, but after reading up, I'm lead to believe it could be a wheel bearing or cv joint perhaps? I am also starting to notice the breaks beginning to squeak when I come to a stop. This is only my first issue with the car.

Next, every so often, sometimes twice a day and sometimes only once a week, I go to start the car and I turn it over and nothing happens. I hold the the ignition in the start position and after a few seconds the car starts or sometimes I have to jiggle the handle that places the car in drive/park. Is my starter going out?

Third, my rear windsheild wiper appears to be a quarter of an inch away from the window, so when I engage it, it never touches the actual window to wipe the rain away. How would I be able to fix this?

I apologize, I hardly know much about cars.

Do you only hear the grinding noise on turns when the 4WD is engaged, or even when in 2WD? Is the turning radius decent, or does it feel like it's binding when you try to turn sharp?

The delayed starting could be a starter issue, a Park/Neutral safety switch (aka: Transmission Range Sensor, TRS), or possibly the ignition switch - not to be confused with the igition key cylinder. You'll really need to check for voltage to the starter solenoid when the key is in the start position and the starter doesn't engage to determine the issue.

The rear wiper parks in a position off the window glass. At least I think the 1999 did this, like the 2000 does. When you turn the wiper on, the wiper arm will move away from the park ramp and the spring in the wiper arm should pull the blade to the window glass. If not, it sounds like the pivot in the wiper arm is rusted up and the spring tension is not able to overcome the rust/corrosion.

-Rod

The grinding happens in 2wd and is intensified in 4wd. When 4wd is engaged, and you turn right, the grinding will actually shake the explorer, almost to a stall. I think the turn radius is fine, it just sounds and feels like a grinding from underneath the car and where the wheel is.