#1) Block time decrease from 10 minutes to 1 minute. (and decreasing reward by / 10 per block)
The block time was not chosen because satoshi liked the number 10. The 10 minute confirmation time reduces the number of orphans that the coin would have. With the larger number of orphans, block reorg will happen more often and most services requires a lot more confirmations.
#3) Apply a system of master nodes where there are 10,000 nodes that receive an equal split of 1% of all bitcoins generated. (Comes out to about $200/month at current USD rates, enough to pay for a dedicated server or colocation space to host the node in a good environment almost anywhere in the world.)
I'm not sure if there is a good way for Bitcoin to implement this without having people cheating the system. Anyway, who is going to pay for it? It is going to require some protocol change and miners probably aren't in favour of this. Its pretty useless for this system since it really just takes the centralisation even more. Not sure how this would help the confirmation time either.\
#4) Reduce the amount of read/writes to disk on a bitcoin full node. I stopped running a full node because it lags everything else my computer tries to do. Not because of the disk space it consumes.
You can easily restrict the number of nodes that can contact you and your disk activity would drop exponentially. It's likely more of a problem with your computer than anything else; I run my node on a laptop thats about 10 years old and it doesn't affect the performance that all. The only time you are likely to experience any effect is when a block is mined (If your computer is really really bad).