Terumot & Ma’aserot

Do we need to separate terumot and ma'aserot from produce found in closed military zones during the War of Iron Sword?

We picked lemons from our neighbor's tree with their permission. Some of the lemons were taken from the neighbors' garden and entered our house through the door. Another part was brought directly from their garden to our house through the window. The lemons are mixed together, so it is impossible to know which lemon was brought in through the door, and are obligated in tithes, and which lemons were brought in through the window and are not obligated. How should we separate terumot and ma'aserot now: Should we tithe each and every fruit, or can we take them all out of the house and bring them back in through the door?

There are people who prepare liqueur from the small fruits that grow on myrtle bushes (hadas) during this season of the year (hereinafter: "myrtle berries"). Is it necessary to separate terumot and ma'aserot from them?

My neighbor has a tree whose branches extend into my property. Am I allowed to pick the fruit without requesting permission?

I recently bought a hydroponics kit for my porch. Do fruits/vegetables that grow have the same halachot for shemitah, terumot, ma'aserot, neta revay, orlah? Also, which berachot would be said? Still ha’eitz or ha’adamah or shehakol?

I picked about 10 avocados last week and brought them home. Do I have to wait till they are soft and tasty to separate terumot and ma'aserot? I think you can eat them unripe though they are not tasty. 
But if I cut an unripe one for terumot and ma'aserot, I will have to throw away part since once cut,  avocados no longer ripen.
Also what do they do in supermarkets where terumot and ma'aserot have been taken but the avocados still need a week or 2 before they ripen and can be eaten?

Is it true that there is an arrangement where I pay money and terumot and ma’aserot are taken on my behalf?

I live in the Old City in Jerusalem. What do I do with my ma’aser sheni?

I separated terumot and ma'aserot from my potatoes, and accidentally cooked the potatoes that I set aside. How do I kasher the pot?

How do we fulfill in our days the Mitzva of Viduy and Bi'ur Ma'aserot?