I started eating hemp hearts for breakfast and I feel I have been gaining weight! For the past few months, I am mostly vegetarian, eating only local beef in the summer months and free-range chicken seldom... an example of my daily food consumption is as follows:
Breakfast: 1/2 cup Yogurt, 1/4 cup granola, 2tbs ground salba, 1tbs flax, 3tbs hemp hearts, few strawberries or half banana
Snack: tangerine
Lunch: mixed green salad, oil & vin, avocado, chopped walnuts, beets, hot peppers, feta cheese
Snack: handful of corn chips, 2tbs hummous or salsa
Dinner: Broccoli, mushroom, spinach, black beans 1/4 skim mozza wrapped in whole wheat flat bread.

Omega 3 fatty acid sources like tuna, salmon, (Don't know if you want to eat fish) flax, walnuts are healthy choices. Your diet sounds pretty good, you need protein, which you can get from legumes, beans and lentils.

Everything above has protein in it, except for the tangerine.. I'm just worried the 'good' fats with be hazardous to my health if I consumes too many..

The two essential fatty acids most important to good health are omega 3-6, but you have to have the right balance. Too much omega 6 can raise your blood pressure, lead to blood clots and cause your body to retain water, As long as your avoiding trans fatty acids as much as possible you'll be fine. And from what your saying your eating, I see no problem, It sounds like your eating well for a vegetarian.

The key is balance. I've taught clients to LOSE bodyfat by ingesting 30% of their daily calories from essential fatty acids.

In fact, I guarantee you that Omega 6 fatty acids will continually show links to cancer in the upcoming years. Why? Because for decades, our diet generally consisted of a 1:1 - 3:1 ration between Omega 6 and Omega 3 EFAs.

Nowadays, it's not uncommon to have a 50:1 ratio!

Since you're primarily vegetarian, you'll hopefully avoid this mess. So keep with the 1:1 ratio and remember that, in general, good fats won't make you fat... caloric imbalance and storage will.

Also be careful with your sugar intake. Watch for the hidden sugars in your diet. Sugar is the secret killer... look up some facts about sugar and it will blow your mind. I stay away from refined sugar I eat only natural sugars (raw honey, fruits, agava) and take in a lot of good fats. I eat all types of fish along with taking fish oils pills, raw coconut oil daily, all types of nuts, olive oil for everything (stone pressed from chili) and I've lost 10 lbs in the last 3-4 weeks. I eat throughout the day 5-6 meals (small) consisting of fish, chicken, veggies, fruits, nuts, greens everyday. I also eat berries daily for a high antioxidant dose. I feel great! Back to the point... with all the good fat intake I ingest, I still lost weight...

I lost 4kg with a 21 day sugar/carb free diet to break my sugar addiction.
After that I've kept really healthy and off sugar and carbs but sometimes I get so hungry like today, I ate 250gr of nuts which have 1200 kcal plus 5 tablespoons full of coconut oil plus 1 1/2 avocados, eggs, chicken and salad.
Can I still lose weight by eating so much good fats or will I start to put on weight again ?