First of all, yes it does. 1 of the main reasons your primary & secondary sex characteristics are as they are is because of the hormones your body produces. You have more testosterone, the more masculine you look. You have more estrogen, the more feminine you look. There are many transgirls who already look feminine in the face before HRT, then get on HRT & just look more feminine because of estrogen. Yes, some get FFS, but not all.
Second, it does NOT "increase weight gain." Testosterone & estrogen just redirect where fat is stored primarily in the body. Pretty sure it's other hormones & genes that determine how much weight you gain or lose, such as the ones that control your metabolism & the like. Whoever told you this is stupid as fuck. This is basic biology.
Third, not always does it shrink someone's dick. There are plenty of transgirls who don't lose their size because of HRT. The main thing it does is it can decrease one's sex drive or stop or make it very hard for someone to get hard. The main thing that causes a dick to shrink is how much you masturbate or have sex, as not letting your dick get hard over a period of time can allow it to shrink. One affects the other in this case, which can result in said thing.
As for estrogen, it CAN affect someone's emotions, yes. Hormones like estrogen & testosterone are some of the main reasons we feel the way we do about certain things. However, making them depressed? Are you stupid? Depression is often caused by a lack of sufficient types of hormones in the brain. With trans people specifically, most of them are already depressed before transitioning & transitioning actually LOWERS depression in their brains because they're finally accepting of themselves & changing their bodies to align with what their brains are telling them.
You're an idiot.