I don’t see anything to worry about there. You have never worked on old cars have you? Put some grease on them and screw them in all the way to cover
Permatex Anti-Seize Lubricant is a highly refined blend of aluminum, copper and graphite lubricants, for use during assembly to prevent galling, corrosion and seizing and to assure easier disassembly. Featuring salt, corrosion and moisture resistance, this lubricant is ideal for marine use.
When should you worry? When the rust starts into the base diameter, the cross sectional area of the bolt inside the threading.
Then you are loosing strength. Usually by then it won’t turn in the nut and is stripped in spots.
Antiseize is very messy sorry