I'm only partway through the game, so can only help a little bit. As far as I can tell, none of the trophies are missable. Most are fairly self-explanatory, but I found a steam guide: https://steamcommunity.com/sharedfiles/filedetails/?id=547024522 that will help if you are having trouble finding some of the secret locations (look for the chests on the maps). This guide: https://steamcommunity.com/sharedfiles/filedetails/?id=467957277 for the steam achievements isn't horribly helpful, but I think some tips for the weapon trophies are in it. Unless you are confident in your survivability, avoid the bounties when they come up as some of those monsters can destroy you fast (learned the hard way). My current run is at 28 hours and I am taking it in small chunks and really slow. You don't seem to be able to really out-level enemies, so earlier areas still need to be taken carefully if re-playing them.
Keep Divinity Cards and Demon Powers for transmutation (as well as any rare weapons). I am using the Cavalier's Outfit since it allows me to sit back and let my Overdrive meter fill... Upgrading it for faster Overdrive. Some fights I run in circles just casting my Death Machine Demon Power. Use the dodge command a lot. I found it helpful to have Vampire Divinity Card (I'm using 10% Life Steal one) as well as Slayer Divinity Card (9.0% of max health on kill), The Tower Divinity Card (50% faster overdrive), The Sun Divinity Card (explosion on overkill for 400 damage that ignores armor) and The Beast Divinity Card (45 armor penetration). Also, you can transmute 3 of the same chest to the next higher chest. Do this until you get a purple chest, then feel free to open it. Purple weapons level in damage as you level so you don't have to keep feeding the weapon you like other weapons to improve its damage.
On Hardcore Hard, all enemies seem to have 120 armor minimum. I have been slowly playing around with replacing some cards with armor penetration to see if I can kill enemies faster. Again, I'm sure some people have much better and easier builds out there, but I have just been doing what feels like it is working for me.
One thing to keep in mind: There is a huge difference between obtaining the plat and obtaining 100% in this game. Hardcore mode is NOT required for the plat, but Hardcore Hard mode IS required for 100%. Hardcore hard mode is frustratingly difficult at times. You can get trapped in an area by enemies and be dead before you have much time to react. I'm sure others can provide some useful tips for it, but I have been focusing on using shotguns and lightning guns (until I found a guitar in Motorhead that I like... now I use lightning gun and guitar). Take it slow and don't be afraid to port back to the main menu or the hub and start an area over. Challenges do not have to be completed in 1 run and secrets are saved as they are found. Personally, I am not working on challenges right now and will go back to them once I finish up the required hardcore trophies (if I don't give up before then). Hope some of this information is useful, its all from playing and starting over a couple of times.