but for sure you have make the different wallet seed when used mobile and pc. I mean don't put it together.
The more instances of the same wallet with the same seed there are, the greater the chances that malware or a user mistake will cause the information to leak from somewhere that could result in the loss of coins. So it's a good idea to have separate wallets, sure.
better for big money to use pc, when small like 0.001, mobile is good, because very flexible if you have travel to anywhere.
It depends on how you use your PC. A computer isn't safer than a phone if the person using it has been infected with malware, clipboard hijackers, password stealers, and generally has no idea how to keep it safe. And if he isn't replicating those activities via his phone (hard to think but still), the phone might actually be safer.
And also: small to you can be even smaller for someone else, or it can be an enormous amount. 0.001 BTC converted to USD is just a tip you leave after lunch, or someone's weekly salary depending on where you are in the world.
