As long as Austin Siebert is consistently making Shorter FGs and PATs, I believe he will be the Lions opening day Kicker. Siebert's noticeably stronger leg gives him a sizable advantage over Riley Patterson.
Barring a major injury, Special Teams are why Josh Woods will either survive the cutdown to 53, be claimed off waivers by another team, or be on the Lions 53 roster at some point this season.
Trinity Benson has a significant advantage to survive the cutdown to 53 over Quentez Cephus and / or Tom Kennedy.
My guess is Kalif Raymond will be the Lions primary Kickoff Returner vs. the Eagles, with Craig Reynolds the Lions player the Lions secondary Kickoff Returner option.