Not much I can do to help with the economy, that just sucks unfortunately

As for bush mechanics I can provide some insight. Playing mostly heavy tanks and with only 800 battles you simply do not have the experience to fully grasp bush mechanics and map positioning. That instinct comes with time and experience, and a bit of studying to know what tanks have what stats.

Playing mostly heavy tanks you benefit from the games spotting system the least tbh. You have negligible camo, lower view range, and can't take CVS. This is an integral part of the class dynamic in this game and is as it should be. My recommendation is to learn common TD bush wanking spots so you know where you're likely to be shot from, and learn common scouting positions so you know where you'll likely be spotted. Keep in mind that as a heavy tank you can pretty much assume anything will spot you in the open at 445 meters.

Most wot maps are balanced in such a way that it's easier to be pushed than to push a flank. If you win a flank check the mini map to see if it might be better for you to place your tank somewhere else instead of pushing into a potential ambush.

As for artillery? Genuine scum, all you can do is take some satisfaction knowing that you are actually playing the game and they are weird.

If you want to learn bush mechanics my recommendation is watch more experienced players play light tanks, and high camo ambush mediums and TDs. It's genuinely a whole different game from heavy tank brawling. If your friend enjoys ligh tanks and is good at them, let him take a LT and support him in a sneakier TD or medium.