Couple of Q's (Beetroot, cucumber AND strawberries?!)

Hey folks firstly thanks for the advice I have received thus far, proud to say I have managed to succeed in not killing everything and have multiple tomato plants with fruit developing! ...slugs ate my cucumbers though, boo,.

So anyway three questions for ya...

1) Totally forgot I'd got some beetroot (bolthardy) seeds a while back, if I were to plant them now could I get a harvest end of September/October, or too late to try now?

2) Cucumber wise the slugs ate two of my plants. my other two were impacted but managed to rescue them. One of them is flowering to a great degree but none seem to set as developing cucumbers thus far (albeit only a few flowers have come and gone, most are in development still or still flowering), the variety is Crystal Lemon if that's any help.

3) Strawberry plants wise I didn't try them, can I sow some now and have them grow over winter in an unheated greenhouse? Or is there a better time of year to start them off?