(1) Proof: From the given condition, we have a$_{n+1}$+a$_{n-1}$=2a$_{n}$+2. Thus, (a$_{n+1}$\-a$_{n}$)-(a$_{n}$\-a$_{n-1}$)=2.
Therefore, {a$_{n+1}$\-a$_{n}$} is an arithmetic sequence with the first term 4 and the common difference 2.

(2) For n≥2, a$_{n}$=(a$_{n}$\-a$_{n-1}$)+...+(a$_{2}$\-a$_{1}$)+a$_{1}$
=4(n-1)+$\frac {(n-1)(n-2)}{2}$×2+2=n(n+1).
When n=1, a$_{1}$=2 also satisfies the above equation.
Therefore, a$_{n}$=n(n+1).
Then, b$_{n}$=$\frac {10(n+1)}{n(n+1)}$\-$\frac {1}{2}$=$\frac {10}{n}$\-$\frac {1}{2}$
Hence, S$_{n}$=10(1+$\frac {1}{2}$+...+$\frac {1}{n}$)-$\frac {n}{2}$,
And S$_{2n}$=10(1+$\frac {1}{2}$+...+$\frac {1}{n}$+$\frac {1}{n+1}$+$\frac {1}{n+2}$+...+$\frac {1}{2n}$)-$\frac {2n}{2}$,
Let M$_{n}$=S$_{2n}$\-S$_{n}$=10($\frac {1}{n+1}$+$\frac {1}{n+2}$+...+$\frac {1}{2n}$)-$\frac {n}{2}$,
Then, M$_{n+1}$=10($\frac {1}{n+2}$+$\frac {1}{n+3}$+...+$\frac {1}{2n}$+$\frac {1}{2n+1}$+$\frac {1}{2n+2}$)-$\frac {n+1}{2}$,
Thus, M$_{n+1}$\-M$_{n}$=10($\frac {1}{2n+1}$+$\frac {1}{2n+2}$\-$\frac {1}{n+1}$)-$\frac {1}{2}$
=10($\frac {1}{2n+1}$\-$\frac {1}{2n+2}$)-$\frac {1}{2}$=$\frac {10}{(2n+1)(2n+2)}$\-$\frac {1}{2}$,
When n=1, M$_{n+1}$\-M$_{n}$=$\frac {10}{3 imes 4}$\-$\frac {1}{2}$>0, i.e., M$_{1}$M$_{3}$>M$_{4}$>..., so the maximum value of (M$_{n}$) is M$_{2}$=10×($\frac {1}{3}$+$\frac {1}{4}$)-1=$\frac {29}{6}$.

Therefore, the maximum value of {S$_{2n}$\-S$_{n}$} is $\boxed{S}$$_{4}$\-S$_{2}$=$\frac {29}{6}$}.