Recently finished Bioshock Infinite on Hard Difficulty and wish to replay it through to collect all the voxophones / sightseerers and other trophies. However, when I wanted to start a new game, it says that it will overwrite my current data. I thought it would create another file specifically for that difficulty level.
So my question is... If I start a new difficulty level (ie. easy mode), can I load whichever chapters I want (since I beat the game already) or do I really have to start from scratch and do everything all over again?
I guess what I really want to know is what the best (and easiest) way is to collect all the trophies going forward... obviously the 1999 mode is a different story but for all the other trophies, should I create a new game on EASY ?
Yep, that's what I would do and still have to do. My first playthrough was on Easy mode and I got nearly all the voxophones / sight seeing areas without looking at a guide. Now that you've played it through on Hard mode it should be a breeze for you to just go through and get those remaining trophies.
Be aware that Infusion Upgrades must be collected in a single play through. For everything else, they can be collected via Chapter Select, but of course 1999 mode doesn't show how many you have collected.
Since you already completed it on Hard, you should just complete it on 1999 to be honest. Just keep track off your collectibles by marking them off on a paper (that's what I did).
You can do easy just for the collectibles, but you're will be doing another play through for no reason if you think about it.
1999 mode is actually "easy". You just need to know how to use your vigors and when. Use most of your Infusion upgrades on Salts first and then for your Shield.
For the last mission, put the Vigor Return to Sender all over the blue core to help reduce damage.