For those having trouble here are my tips to being successful.
1. Don't worry about loosing members. You are going to loose AT least one member (at best) by the end of the game. In fact the best strat to take is always support, defend the biggest money makers right from the start (like Russia, USA, UK, China, etc) and unless you are desperate for the reward let the low income peeps (South America, Most of Africa) fend for themselves and sacrifice them as needed. In my current game I lost 6 peeps but that's fine, I have a smaller group of nations to keep happier and it's easier to maintain.
2. Start building sats ASAP even if you don't have the capacity for them they will be in reserve so when you do build more uplinks you can launch them right away.
3. No need to build more then 2 labs and 4 workshops. Make sure they are next to each other so you get the bonus.
4. one heavy or assault should ALWAYS have a arc thrower on him/her. Critical to capture new aliens which opens up new research paths. Also their equipment is captured and goes into your armory.
5. develop heavy armor asap (see tip #4) before worrying about new weapon development. Keeping your peeps alive is more critical to start then dealing more damage.
6. Work the same group of 4 (one of each class) in the beginning until you get a sgt then capt rank. As you do spend the monies in the officer school and increase your squad size to 5 and 6 respectively ASAP. That extra peep on the battlefield helps more then you can imagine. When you get your squad to 6 the best load out is 2 heavies, 1 assault, 1 support and 1 sniper. The 6th position bring a newbie you want to train/get xp. If you don't need, want a newbie then another assault or low ranked peep you want to help train.
7. ALWAYS have backup. Each mission rotate the squad so you build up more or less equally of 2 or 3 of each class. This way if you have someone sidelined due to being badly hurt or KIA you have someone else who can take their place without much if any loss in skill, abilities.
8. Overwatch is your friend. Move slow, using cover as much as possible and ALWAYS use overwatch. Dashing ahead with no overwatch/moves and running into a large group of aliens is pretty much a death sentence or at the very least a front row seat to the chunky salsa effect for some of your squad.
Hope this helps.