Aha! There is no correlation of adding a GA of a burnt site and rankings… there is no way I can believe that your GA account that has been previously used for a website that was burnt by the search engines can kill the rankings in SERPs…
This must be something different!
- Unless you are not using too many H1 on each pages its great!
- Changing title can hurt the rankings if they are not keyword focused!
- Adword campaign can never kill the site rankings if you are not changing anything in the website for this purpose… usually for adwards if you add/include more pages, its good practice to exclude those pages from indexing!
- Adding a Hello Bar not really!
Check your page time speed and may be due to (improperly) adding of codes page time load might went up and effect the ranking negatively.
H1s and Titles can hurt if they are not keyword focused but other then this adding GA or Hello bar can’t hurt Google Rankings in anyway…

