Spring links are not always safe, most m/cycle chains are now riveted.
The link you have with the end plate and two pins has a slightly softer steel in the pins which means it can be riveted.
This can be done by holding a lump hammer behind this link and using a ball peen hammer to hit the end of the pins gently and precisley to rivet it together. I do mine like this but if you do not feel confident to do this a m/cycle mech will do the job in about 5 minutes.
The four seals are to be fitted before doing this as oil seals and to stop grit getting into the chain.