The best way to gain "good" weight is to increase your healthy macros (fats + carbohydrates) slowly. Try adding some more brown rice/sweet potatoes/oatmeal or avocado/nuts/MCT oil into your daily meals. The key is doing this at and gradual rate of time and building from there. 
Track your calories too! You can use apps for this and see what you typically eat each day and increase by weekly to make sure you are getting in enough food. :)

Thank you!

Yes of course!

I live faithfully by "you can't outwork a bad diet" mentality. Unless you are born with freak genetics, seeing abs requires hard work in the kitchen. 
If you want to really see a change, try tracking your food for a week using myfitnesspal or any other macro tracking app. Log every single bite you take and evaluate. More often than not, we fool ourselves into thinking we are eating better than we are in actuality. 
On the flip side, make sure you are eating enough of the "good stuff" to keep you full and not wanting to eat the "bad stuff".

I'm a vacation/trip planning gym freak. Before I book any trip or holiday, I check out the hotel gym ahead of time or map out the closest gym. In large cities, they are literally everywhere all over the world! Even on a 2 week road trip in Scotland I managed to find a gym within 20 mins of 90% of my travel spots. 
I try to workout 5-6X a week.
If you truly are in the middle of nowhere and you don't have a gym, there are a lot of at home things you can youtube with little to no equipment. It might not be as great as a workout in a fully equipped gym, but it'll be better than nothing! (Or stretch for 20-30 mins! -youtube vids on this too!)

I know that fasted cardio isn't any more effective than fed cardio, yes.
For me, it's more of a personal preference. It's the first thing I do in the AM. It helps wake me up, and it sets my pace for the rest of the day. Knowing I have already worked hard on cardio, the likelihood that I deviate from my plan/diet drop much more.
As far as it burning muscle. Any type of cardio puts you at risk for burning muscle along with the cardio. I would be curious to see the study that showed fasted vs fed. 

The gyms I go to don't have any sadly :( 

Waaaaay back in the day I did p90x at home. I was terrified of the gym. After I finally overcame this fear, I have found the gym environment to be extremely motivating. 
However, I am fortunate to live near several gyms, and not everyone has that luxury. Home workouts can be extremely beneficial for cutting/losing weight.

Simply put, think of your metabolism as a campfire. You need to constantly put wood on the fire to keep it burning. If you don't, the fire goes out. Same with dieting. You should constantly be eating small meals throughout the day to keep your metabolism fire stoked. (4-6 meals daily)

Don't drink sports drinks. They are pointless calories.
Don't eat things with high fructose corn syrup. Your body doesn't know how to process this, and stores it as fat. 
Don't be afraid of salt. Salt is a natural mineral that your body needs and contrary to popular believe WILL NOT MAKE YOU FAT. It may make you hold water, but water retention does not = fat.
Keep your food clean and simple! Your body will thank you.
Drink tons of water to help you feel full and digest food. 

When I have clients that have had any major surgeries or medical conditions, I ask they ALWAYS get clearance from their DR before they begin any type of strength training. Since every injury is different, there is no perfect remedy that works for every individual. 
After gaining clearance from your DR ask if there are any movements you should not do, or what your limitations may be.
After that, I would work on range of motion, mobility and stability (depending on your current age, health and activity level) this can be quite strenuous! Build to do bodyweight movements.
Again, this is all based on your your MD has prescribed and after they have given you the green light to being active! 

I'm going to take a guess at this... 
"Can you still be a vegetarian and workout out on the same levels"
There are countless vegan/veggie bodybuilders out there! It is possible. I, however, eat meat for my protein. 

Caffeine is actually a vasoconstrictor. So if it can technically take away from your "pumps" at the gym. However, most pre-workouts have other ingredients that help promote the "pump" that is robbed from the caffeine. Most people would rather have the "FUCKYEAHLETSGO!" attitude achieved with high amounts of caffeine than to feel sluggish.
I drink energy drinks when I need to train clients or I am in class. I drink pre-workout before gym (sometimes without caffeine depending on how I feel or how much I have already had throughout the day)

When I am dieting, I eat nothing and do fasted cardio and then have my breakfast (egg-whites + oatmeal)
Currently, I have a handful of cashews to go with my AM coffee most mornings :)

You don't get fat in a week, and you don't get lean in a week.
Seeing the results from dieting take time. The best thing I have found is to have a start date, and know just how many weeks/months I am going to be 100% on the diet. After awhile, things become a habit and you develop the "it's a lifestyle" mentality.

Just keep going! Even if the scale doesn't change in a week, if you are dieting + exercising properly, you will get there!