A cupboard with a glass window might help you...
As for getting 'hacked' - I think that's the first time I've seen such a warning. In many cases the smart devices have some sort of 'App Store' where you can download applications (for iPlayer, ITV Player, 4 on Demand, Demand 5, etc) and no other options exist, no anti-virus App in sight, so frankly I'd tend not to worry too much for now.
Not sure what "Smart TV" you plan to buy and I am no expert - don't even have a TV licence (but have a sister and friend who have bought so-called smart TVs, and been somewhat underwhelmed by the features). I have a NowTV box (costing 9.99, and subscribed to the movies for 3-4 months at the end of last year) which has players for all the "on demand" (ie not live) TV shows.
It's about the size of a beer mat, plain white with a small (white) LED that isn't very bright, and perhaps 1.5cm thick, with sockets on the back for power and HDMI. Unless you have tried out the TV in a shop for at least a half hour for browsing etc and feel sure it does what you want, I'd get a dumb TV and add a NowTV box as I think the extra for a 'Smart' TV may be a lot more than a tenner (OK, 20 quid if you get it with 2/3 months of Movies/ Entertainment - you need an active NowTV account to first register it, so paying 9.99 for it online will not get you very far).
The NowTV box is wireless and connects to your home broadband, and needs a minimum of (from memory) about 2.5 Mbps for downloading decent quality TV. I stream a fair amount from TWiT.tv ("This Week in Technology")... there's quite a lot of interesting info about Apple, Android, Windows (eg the new Windows 10 out next year), iPads, Google, security, etc.