Read all the books you mentioned and a few more.

I def think you can still beat online micr/low stakes MTTs by sticking to the stuff described in the Harringtons. Same holds true for low/mid live MTTs.

THe books are very good fundamentals. 

Kill Everyone: very good book for the modern MTT player. Covers a lot of the things one should know about the dynamics of MTTs

The Raisers Edge: allthough i am a math nerd and like all the graphs and tables and equations i think its a bit to theoretical with to many assumptions. But, its very good to learn how to do the things yourself based on your reads.

What i like as a quick read is “The tournament rules” by Chris “Fox” Wallace. It sums up the basic bullet points of playing MTTs (not calling more then 5% eff stack with spec hands). its easily read in 1-2hours.

also the series by rizen,apestyles and pearljammer have some good points in it.

But, with a subscription here and the willingness to watch tons of videos actively (taking notes) you are in good shape to get better.

I basically would suggest kind of a studying schedule for you.

For example watch a video series form a pro that has a similar style. Choose 1-2 things you want to apply(3betting light etc) 

then play a session and look for spots where you can apply the concept you learned. try it out and save the HH for your success and failures and discuss them.

paritcipte actively in the forums. dont be afraid to ask basic questions even if the thread seems to be very advanced. There are not a lot of forum trolls in here (tbh i am prob the only one from time to time). so you will get good responses

also a great way to improve your game but a more expensive one is to take a personal coach. Some coaches are also doing backing deals with their students. just check the fourms here or elsewhere.

if there are any questions feel free to ask.

cheers