Frankfurt(Oder) has some churches, fountains etc. and you can walk by the river. Slubice is IMO not much of interest unless you want to buy cheap(er) booze or cigarettes.
Frankfurt is quite interesting - it has the Europa Garten, an interesting central square that screams DDR, the Marienkirche is worth a visit, and there are some reasonable pubs. Słubice is a typical small Polish town - not much happening, but it has a very good restaurant (
http://www.douane.com.pl/) and it's pleasant enough to wander around for a couple of hours. Just get away from the main "Zigaretten Allee" and it's fine.
Any opinions on Frankfurt(Oder) and Slubice (sorry can't type the Polish letter), both relating to transport and in general? There does not seem to be much cooperation between the two areas
No, there isn't. There are a lot of tensions between the two cities, and while there are people doing their best on both sides to integrate them, the two never really developed together in the same way that Gorlitz/Zgorzelec did. The reason is historical: after WW2, Gorlitz/Zgorzelec always had an open border crossing in the centre. In comparison, in Frankfurt/Słubice, the border there was closed for quite a few years after the war, and there was always quite a lot of resentment from both sides towards each other. Then, in the 1990's, both towns were quite dangerous - Poles were beaten in Frankfurt by neo-Nazis, while Germans were often scammed on the Polish side. None of that exists today, but people have long memories.
Frankfurt wants to build a tram line to Słubice (as existed before the war), but financing is the problem, as neither side has the money for it.
Regarding transport, my advice would be to take the train to FFO, then walk from the station to Słubice via "Der Oderturm" in the centre of the city. While the old border crossing buildings have finally been demolished, the area around the former border crossing still retains a certain character to it.
Don't rely on the Polish train connection, and the station in Słubice is nowhere near the town anyway.