Need tips and help about WC with vassal swarming Austria

[Blood4u]

Just finished my first full playthrough as Austria where i learned so so much about the game but i also i screwed about 100 years i would say by not understanding what are heretic princes,how to deal with them,then that i have to pass an act for my princess to rule HRE ,not having Ia because heretic princess,losing emperorship,new emperor kept losing hre lands to big powers etc.I also reovked privilegia pretty late and learned that i can give land to my huge amount of vassal to not get overextended and they would core it up thus making wc seems doable if i actually play proper for the first time ever.

I do howeer have some questions in regards to some grander turning-points that i don't fiind in general guides so im coming to ask you guys that have more experience inthis case

1..Should i integrate Bohemia/Poland/Lithuania/Hungary before revoking privilegia?I had inherited everyone via monarch dying beside lithuania before revoking privilegia and when i did i was integrating lithuania,and he was 52% loyal as that happens,if i have had them all would they be disloyal?
2.What cb's to use when conquering?When i reached late game i would use imperial cb on everyone just to get the land but against castile/gb i was using colonialism when i wanted to get their colonies first ,do not know which one is more efficient or why colonialism was working only against african colonies although i had 2 in new world.What cb should i use early on ,just normal fabricate claim and expand?
3.How do you tackle expanding and revoking privilegia?Do you expand while trying to revoke privilegia or focus on that and use the vassal swarm?How much land should i have to keep my vassal swarm in check?Should i be at 99% overxtension always and keep using admin for it ?
4.How to deal with european colonizier,continents management?In my playthorugh i snaked to India and Japan to get the achievments,so it was easy to juggle AE until AE didn't matter cause i was half the world but how do i know in which way to expand?Do i have to deal with castile/portugal/gb/Russia early?Do i let them colonize and then just beat them for colonies?Do i try to snake my way so i have multiple fronts?Or do i just keep fighting wars in the same from and keeping truce timers up?
5.What ideeas are privotal? I started with diplomatic which seems important for early HRE stuff then i went quantity cause wars were taking a toll and then economics because i kept having loans even though i was barely using mercs and developing my country properly.Is there a best set to get as Austria ?Was thinking i might need religios to convert.
6.When should i take my golden age?Pretty straight forward i took mine during the age of absolutism but i have no clue when it's the best,feels like in the first age you only reap the benefits for half of the time.

Thank you to any kind soul that takes time and helps me with any of the questions.

 

[Livigy]

1. I don't really have much advice with the HRE I tend to break it instead.
2. The other cb you should look into more is reconquest. If a large nation gets absorbed or fails they will still have cores for a time and you can use that to revive the nation and reconquest with only 25% AE. Early game some good targets are Byzantium or reviving Syria and mid game you may look to revive Aragon, Novgorod, Timurids, Ming, Mamluks, Lithuania etc if they fail or get integrated into larger tags like the PLC/Spain. You may also want to look into diplo vassaling for additional expansion paths that do not generate ae as well as pu's if you are playing a Christian tag.
3. There should be some decent guides on vassal swarms/Austria runs that you can look into. After you get into age of absolutism staying just under 100% over extension is a likely goal if you are strong enough that coalitions are no longer a relevant hindrance.
4. With colonisers some alternative ways to deal with them is to PU them either through chance or claim throne, integrating them will give you their colonies, or alternatively annex them entirely will also transfer their colonies to your control.
5. Diplomatic, Administrative are generally great. Influence is also useful if you plan to expand with and annex vassals and humanist is also useful to prevent wasting half your time/manpower dealing with rebels. However if you are a particularly religious tag and if you follow a faith with a lot of monuments you can invest into then religious ideas may be suitable to help prevent endless rebels.