Taxable account help?

[G123]

This is my first post.

I am 39 dh is 42. We have 2 kids.
Kid 1 has 4 year pre-paid college paid in full.
kid 2- open Utah 529 couple months ago and put 17k in it. Will need to continue to add to it.

We have no mortgage ( house paid for years ago) or car payments or any debts.

Dh has 401k with 550k
Roth ira- 27k
ESPP- 125k

Me have Simple IRA 100k
roth Ira 80k

Jt. Account 64k.
All accounts with fidelity.

We don't have many choices for dh 401k. With the Simple, both Roth and joint we used Gone Fishin portfolio which is
15% vanguard TotalmStock Market (VTI)
15% Vanguard Small Cap (VB)
10% Vanguard European (VGK)
10% Vanguard Pacific (VPL)
10% Vanguard Emerging Markets (VWO)
10% iShares iboxx High Yield Corporate Bond (HYG)
10% Vanguard Total Bond Market (BND)
10% iShares Lehman TIPs (TIP)
5% Vanguard REIT (VNQ)
5% Market Vectors Gold Miners (GDX)

We have 20k to invest in our joint account. Would you rebalance? Buy something else like Vanguard Total Stock Market Index fund (VTSAX)? I only work during the school year and plan to add to the joint account. I have not been doing this in the past. Is it bad to rebalance too often? Investing is very new to us but I really want dh to ER in 10 years when youngest graduates HS or sooner. I think we need to build up joint to have something to live off till dh is 59 1/2. What would you do?