Hi! Even though I am not a brand spanking "new" grower (I am a Grandma) I am kind of new to the "New Ways" of all the high tech lighting and stuff. (Makes ALL of it much easier for ALL indoor gardeners!) ONTO your questions. First, I see you are a "Kyle Kushman" Fan. Me too, everything I have learned over the last 8 years has been from him. He is Now with Homegrown Cannabis Co. (as a consultant/breeder etc) and he posts a crap-ton of videos on both Homegrown Cannabis site as well as on YouTube >
https://homegrowncannabisco.com/gro...-grow-marijuana/how-to-grow-cannabis-indoors/
I learned and did his "Kushman Chiropractics" and his trimming style etc. If you like his as a teacher, my biggest "take away" is choose who works BEST for you... OK, onto your questions.
1) I DO Topping and FIMming on plants when they are between 4-6 weeks (If I am going to on that plant). I grow MAINLY indicas and Indica Doms.
2) YES, you certainly CAN pollinate one branch only (on EITHER autoflowers or Photoperiod). There are sprays for that. Just spray the ONE branch and the plant will self pollinate itself (or you can help with a soft Q-Tip). Many AUTOFLOWERS will sometimes "Hermie" (Hermaphrodite) on themselves if stressed. I have NOT seen this in a few years, so genetics MUST be better on the Autos. But, watch them. They sometimes can pop up some seeds on you! Save them and use them for any experimentation (OR...Feed the local birds, they will love you forever!)
3) I do not ever use trellis. I just don't. I use SOG (Sea of Green) I am a SOIL grower in pots no larger ever than 5 gallons (Usually 2-3 gallon fabric pots) since I grow INDOORS it makes it very easy for a 60 year old grandma to move her plants around in my tent or turn them to get the best light etc.
4) Gender reveals. The more "grows" you do, the more strains you grow, the better you get at spotting it! Males TEND to "develop first" they FOOL you, little "whisker and then a ball sack thingy and a flower. Boom. Male. Be CAUTIOUS with male cannabis pollen!!!! It can go everywhere if it POOFS (releases it's pollen)... And you can ruin and entire tents harvest. (And possibly future harvests!) so, be cautious with MALES plants. No reason to fear them IF you are breeding. I started learning seed breeding after I had at least a few good 5-10 grows under my belt and I felt really good about taking care of my cannabis plants and any problems (without feeling I had to run to Dr. Google).
Last but not least...EVERYONE has an opinion. Do what works for YOU. Being "New to the game" is fun and exciting! You haven't developed any "bad habits" so can experiment with a variety of styles and such. Some old growers we can be stuck in our ways. However I have never had anyone complain about my small, potent craft-medicinal grows. So, I go by REAL world comments.
Best of luck and always keep on growing with a LIGHT heart, that is the ZEN of it!
Warmly,
Jackie~
PS: The attached photo was a G13 (Seeds) I got from Homegrown Cannabis Co, that had a rare "throwback gene" to a chocolate Thai. Really striking purples! Enjoy your growing adventure!