Aye, take a look at this. https://feedback.minecraft.net/hc/en-us/community/posts/360047514492--Java-Edition-Performance-Enhancements-For-Minecraft-Servers-Multithreading-
If you use the JDK instead of the JRE then you can use the following command line to force the JDK to use all available cores for optimising Java itself ALSO on ParallelGCThreads add the number of cores you have minus 1:
java -server -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=7 -XX:+AggressiveOpts -Xms1G -Xmx8G -jar craftbukkit.jar
Depends on games, PUBG, Fortnite, GTAV runs on Ultra 4K at 60 and 120ish at 1080p on my 1070 on my laptop (not mobile, not max-q)
You should do just fine with a 1070 Ti
Yes, get a Chromecast Audio https://www.newegg.com/Product/Product.aspx?Item=9SIA2F85NG6782&cm_re=chromecast_audio-_-15-597-008-_-Product
Amazon removed Chromecast Audio so Newegg or somewhere else is your best bet.