questions about the bigwig files

[FTD2018]

Hi ,
I have recently read your paper published in nature "Regulatory genomic circuitry of human disease loci by integrative epigenomics". It's a good resource for studying gene regulation and excavate candidate variants in disease loci. And I want to download the imputed "bigwig" files (H3K27ac) for a visualization for a genmoic region across different samples such as below:

But I have some questions:

1. Is it suitable for just adjusting the Y axis across different H3K27ac bigwig files to the same range, such as [0, 5] ? Shoud I need do more normaliztion works across different H3K27ac bigwig files to compare them in the same level?
2. Is the bigwig file is just individual file like "bamCoverage" function in deepTools or had been normalized against the input like "bamCompare" function.
   Do you have any suggestions?
   Looking forward to your reply.
   Thanks
   Xiaopeng