If these so called Free WiFi connections you're using, like at a coffee shop for example, there's going to be no way around login screens.
Just because you live in an oppressive country, there's no need to use public wifi to gain your freedom, that's the point of the VPN!
Going over the VPN with BolehVPN is going to be encrypted, there will be no way for the ISP to censor or opress you, because you're using servers in different countries that the ISP will know nothing about...