I dont think its safe because we can be hacked without we even noticed about it. But mostly i think some wallet didnt have enough protection, some only used private key to gain access into their wallet without any other secondary protection. My mew was hacked a few weeks ago without i even noticing about any changes in my computer and after that i took counter measurement to store private key and any other thing necessary to gain access in offline storage.
4. Using the hardware wallet is advisable but looking at the cost you may prefer focusing on the first three points.
5. Do not use public internet and I am pretty sure if you access wallets like that then you will loose your money.
Using hardware wallet is mostly advisable but how do we know that the wallet didnt have any flaw in productions? And i dont know about public internet, i used home internet and i dont even know how my internet was compromised as i also got a total antivirus which block ads and anything. But i guess no matter what, any hacker will always be more cunning then people like me 5. Do not use public internet and I am pretty sure if you access wallets like that then you will loose your money.