I got my first international shipment of seeds two days ago (seeds from Borneo)...
Those seeds don't look bad...
You have to start with fresh seeds, for sure, but a lot can go
wrong afterwards...Still, your best bet is to start with the freshest possible seeds...
If you are just starting with exotic tropical seeds, I would suggest you first gain some experience with
easier and cheaper seeds. After a while you kind of know which will germinate and which will not.
There are some basic rules, like floaters usually do not germinate. Moldy seeds are usually already
condemned.
In my experience, it is very easy to get the sowing medium too wet. I like to use coconut coir and soak it well, but then
I try really hard to squeeze out as much water as possible.
If the seeds also get too warm they will die.
Unless you have a good setup, germinating seeds in the colder months is more difficult. Whereas
in the summer months, fresh seeds will germinate readily.
Impatience also kills a lot of seeds. Avoid poking the sowing medium to check the seeds all the time...
Good luck.