1. I have a ton of Biblical names. Would it be odd if all but one boy had a Biblical name? (Ex. Isaac, Levi, Simon, and August)
I don't think it would be odd at all because names like the ones listed are relatively common and have the same vintage-y feel as the other name. If that makes sense. Like Hezekiah, Esau, and August might be weird, but the sibset you listed is great.
2. I keep coming back to names that end in -er. Is a two syllable name ending in -er (Jasper) too much with a two syllable last name ending in -er?
No, I don't think it is too much, unless you have Jasper Casper or something of the like, haha
3. I seem to have a love of names that start with "t" or "th" as middle names. I can't use them all so I'm looking for opinions on which one(s) to use. These are: Tadgh (Teeg), Tamerlane, Tancred, Thaddeus, Thane, Theron, Tiago, Torben, Torbjorn, and Torin. (yes, that's a lot of Tor. We both like Nordic mythology and Tor is easy to translate.)
Torin is my favorite, so handsome! I also really like Torbjorn, Tiago, and Torben.
Lorcan Theron - Not my particular taste, but I like it. I want to meet a kid with this name.
Stellan Nicobar - LOVE Stellan, such a handsome, well-aging Scandinavian choice. I like Nico, but never really been a fan of Nicobar.
Jasper Dante - Though Dante isn't my style, it is incredibly handsome with Jasper. Great combo.
Casey Caradoc - not my style
Theo Evander - Really great! Theo is adorable, and Evander is a really strong name to balance it out.
Jeremiah Oisin (osh-een) - like this a lot.
Ronan Amadeus - Ronan is very handsome, but I can't even read Amadeus without singing it
Gregory Lir - I've always though Gregory, esp with the nickname Rory, is cute. How is Lir pronounced? I'm saying it "Leer"
Simon Thane - Nice. Simon is great.
Sebastian Willem - Sebastian is nice. I've always prefered Wilhelm or William to Willem, sorry
August Kane - Very nice, handsome combo.