I'm not a teacher, but I think you are demonstrating excellent fluency in written English.
Good to hear from you again. How are you? I hope you are (very-omit) well. I've got so much to tell you that I don't know where to begin!
You asked me about my past dilemma - to study photography or painting. In the end I chose the photography course, because it's more
suitable for me. - this sounds just a bit odd. You means something like, 'more up my alley'
'it's more in line with what I want to do when I finish.'
Ask yourself, why is it more suitable, and this may suggest another word to you.
There are 10 people in the group. All of them are very friendly and our friendship has developed quickly over the weeks of our acquaintance. The course is very interesting and enjoyable, because we travel a lot to practice our photography skills. The most enjoyable part for all of us is the landscape and the wildlife photography. I have enclosed (to the letter-omit) some of my
captured - we talk about capturing a scene etc on flim but we don't say, 'captured photos' ie as an adjective. Perhaps you could rephrase that bit.
photos. I hope you (will) like them.
If you are telling him that you will be sending these photos next time (ie in the future) than you are hoping he 'will' like them when he gets them. But they are in the letter you are sending, he has them in his hand, so no need for the future tense. Just because there may be a couple of minutes reading the letter before he looks at them still doesn't require the use of future tense.(lol)