Welcome, Fekdrink, to the game!
You asked a number of questions and I'll try to help.
First, you have to understand that there are players who have been here for years and who have a lot more to offer you than I can (and they will if you ask!).
Here's what I think (you can look up my stats and be underwhelmed by them - but nobody is playing for cash at WGT).
1. Yes, buying better equipment will be necessary. However if you spend time reading the Forum, you will find "Legends" who used 'free' starter equipment for quite a long time. How fast you wish to advance is up to you.
2. Yes, new equipment costs credits - many have watched videos and taken surveys to support this 'habit' (obsession).I have read of a number of people at the level of Legend who state that they have never spent a 'cent' on the game (a.) I'm nowhere near that level and (b.) I've spent a lot of cents buying equipment.
3. Choosing the equipment:
Personally, I think that you have assembled a GREAT list of clubs FOR THE FUTURE.
I have the R11S 3 wood and R1 and love them! At Lvl 48, I think that the R1 driver is a 'no brainer' - no doubt someone will disagree - but what other driver offers that range, precision, and forgiveness?
Most of the better players here recommend against the hybrid - instead recommending 3 wedges (in addition to the PW that you bought with your irons)
The other high level clubs that you've listed will be great LATER. Not a day goes by that I don't look ahead to the day that I can upgrade to the "BIGGER & BETTER" clubs because I just know that the "better one" will make my crappy approach shots fall into the hole and make all of my 60 ft putts fall (if ONLY I COULD READ THE DAMNED BREAK!!)
I think you see the point - certainly get a better Driver and Wood and then learn to use all of the clubs in your bag -- OH and Before I forget -DON'T BUY A BAG - IT'S GINGERBREAD AND DOESN'T CONTRIBUTE (one iota) A DARNED THING TO YOUR GAME!!
4. Better Balls - WOW - there have been so many threads written about this that .........
The flight characteristics of the balls matter when you have enough experience to take advantage of them!
If you have a problem with the speed of the meter (AKA 'Feel'), spend a little more for balls that are slower (have more 'Feel' dots). If your eyes are getting weak (like mine), consider buying the 'vapor' balls (LOL at myself here - as if seeing the WGT generated interpretation of my missed 'ding' shot will make a difference on the next try).
This much you, probably already know! I suspect, also, that you realize how important it is to master the clubs in you bag - and know what they will do under playing conditions - SO WHADDA THIS GOTTA DO WITH BALLS?
If you keep switching between the Callys, Nikes,WGTs & TMs what you're doing is confusing yourself!
At your level, IMO, you should be learning about 'spin' and recovery from muffed approach shots. IOT do that you have to use a ball with more than 1 dot of spin. Many players with stats that make mine look puny (actually most stats do that) use WGT cheapies - I can't - the meter moves too fast - but the Cally 33+, gives me the feel, spin,etc. that are comfortable - so that I can learn to control my clubs.
PICK 1 and use it - until you learn your clubs!
4. Sub par rounds - Man, I gotta pass here and let someone who has them, on a regular basis, answer that!!
5. It's a game - It's a game - it's a game - (Repeat this often enough and you may even believe it!! ; )