...my landlord said if I call the police one more time that he was going to write me up. He obviously doesn't want me calling the police, but why?

Over a 10 week time period, that averages out to 3 calls a week to police and 2 calls a weeks to your LL. No offense, but that's a lot of complaints that don't seem to be achieving anything. If the police need to be continually called back to the same place, does that indicate they're not finding any laws being broken, nothing illegal? Aside from noise & the parking situation, what other kinds of things are you calling about?

And, more imporantly, does he have the right to keep me from calling the police and threaten me with eviction especially when the other tenant is in the wrong? He says I'm to get out of my car and go knock on her door every single time I want to come home or leave. Is this really how this works??

No, that's not how it really works. But after 52 calls and counting, your way isn't working either. What exactly is it that you're hoping to accomplish? IOW, what is it that you want your LL to do? Not taking sides, but it seems like there are a lot of blanks not filled in here.

I was trying not to get too opinionated in my post, hence "the holes". The police can only tell them to be quiet and say it's up to the LL to deal with them. Though the police did tell these people they would be fined if they were called out again. There are some home owners on my street who noticed all the bicycle and foot traffic at all hours of the night since these people have moved in, and I pointed out the camera pointing down the street watching everyone as they come and go. The tenants claim it's "to keep the drug addicts from stealing their stuff". Drug addicts whom they brought with them when they moved in! Anyway, one of them eaves-dropped on a conversation between me and one of the home owners so they know I'm not the only one who is aware of their suspicious behavior. Things have quieted way down the last few days so we will see how long that lasts. I guess my main question was if the LL has the right to tell me I can't call the police? I've lived here a year and this is the first time I've had to call the police on anyone, so you'd think he would wonder what is going on rather than threaten me to not call the police.

dear spry,
I also had this issue. It was actually becoming a dangerous situation and so is yours if they are doing drugs out of there. My landlord also didn't want to do anything about it, but once she told them I was complaining, she put me in a dangerous situation.

Look at your contract, see if it states anything the LL hasn't done for you even if it's just fixing something and what the LL responsiblities are.

Then get a copy of your state's Landlord/ Tenents Rights Acts.

Most of the time, as a tenant, you can give a written notice on something that has to do with your contract.

For example, my LL wouldn't fix my dryer (the reason i moved there was the washer/dryer). It had "arched" in the wiring catching the ceiling on fire a little bit.

This put me in a dangerous situation, so I sent her a CERTIFIED (THEY HAVE TO SIGN FOR IT; EVIDENCE) letter asking her to fix it within 30 days. She did not. It gave me the way out of my lease. Because LL also have responsibilities. I did NOT get my deposit back, but that was ok, but I also didn't owe for the months left on the contract.

You can call your city officials and ask to speak with someone who might be able to get you a copy of the LL/tenants rights acts. They probably have heard about this landlord before through other complaints.
Again, check your contract, if it says no loud parties or people who are not contracted to live in your neighbors apt. living there, then you have a case but you have to send a certified letter.

Hope this helps. I ended up finding a beautiful little 1 bedroom townhouse (i know, sounds odd) with the best neighbors and the reason the landlords gave it to me was because the first thing I said to them was, "I don't want someone who parties all night or is extremely loud". This showed them that I was NOT going to be that type. I love where I live and I'm lucky no one lives above or below me.
Good Luck! and get out of there...it's unsafe.